{"schemaVersion":"0.2","name":"Toolkit Shelf Formula Catalog","site":{"name":"Toolkit Shelf","url":"https://toolkitshelf.com"},"reviewedAt":"2026-06-06","counts":{"formulas":294,"tools":295},"note":"Formula entries mirror visible Toolkit Shelf pages. Planning, health, tax, finance, and business outputs are estimates unless a page states an exact conversion or formula.","formulas":[{"slug":"percentage-calculator","title":"Percentage Calculator","url":"https://toolkitshelf.com/tools/percentage-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.percentage-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Percent","Base number","Part","Whole","Original value","New value"],"resultLabel":"Percent result","formula":{"expression":"X% of Y = (X / 100) x Y; percentage change = ((new - old) / old) x 100","label":"Percentage formulas","note":"Use the first formula to find a percent of a number. Use percentage change to compare an old value with a new value."},"example":[{"label":"20% of 150","value":"30"},{"label":"45 out of 60","value":"75%"},{"label":"80 to 100","value":"25% increase"}],"sources":[{"href":"https://openstax.org/books/prealgebra-2e/pages/6-2-solve-general-applications-of-percent","label":"OpenStax","value":"Covers basic percent equations plus percent increase and percent decrease in Prealgebra 2e."}]},{"slug":"percent-change-calculator","title":"Percent Change Calculator","url":"https://toolkitshelf.com/tools/percent-change-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.percent-change-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Original value","New value"],"resultLabel":"Percent change","formula":{"expression":"Percent change = ((new value - original value) / original value) x 100","label":"Percent change formula","note":"A positive result is an increase. A negative result is a decrease."},"example":[{"label":"Original value","value":"80"},{"label":"New value","value":"100"},{"label":"Percent change","value":"25% increase"}],"sources":[]},{"slug":"average-calculator","title":"Average Calculator","url":"https://toolkitshelf.com/tools/average-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.average-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Numbers"],"resultLabel":"Average","formula":{"expression":"Average = sum of values / number of values","label":"Average formula","note":"The calculator ignores text and uses only valid numeric entries."},"example":[{"label":"Numbers","value":"12, 18, 24, 30, 36"},{"label":"Sum","value":"120"},{"label":"Average","value":"24"}],"sources":[]},{"slug":"fraction-calculator","title":"Fraction Calculator","url":"https://toolkitshelf.com/tools/fraction-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.fraction-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["First fraction","Second fraction","Operation"],"resultLabel":"Simplified fraction","formula":{"expression":"a/b + c/d = (ad + bc) / bd; a/b x c/d = ac / bd","label":"Fraction operation formulas","note":"The result is simplified by dividing numerator and denominator by their greatest common divisor."},"example":[{"label":"First fraction","value":"1/2"},{"label":"Second fraction","value":"1/4"},{"label":"Result","value":"3/4"}],"sources":[]},{"slug":"date-calculator","title":"Date Calculator","url":"https://toolkitshelf.com/tools/date-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.date-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Start date","Compare date","Years","Months","Weeks","Days"],"resultLabel":"Calculated date","formula":{"expression":"Calculated date = start date +/- years, months, weeks, and days","label":"Date calculator formula","note":"Months and years are applied first so calendar dates stay closer to normal month boundaries."},"example":[{"label":"Start date","value":"May 25, 2026"},{"label":"Add","value":"14 days"},{"label":"Calculated date","value":"June 8, 2026"}],"sources":[{"href":"https://www.iso.org/standard/70907.html","label":"ISO","value":"ISO 8601 describes representations of Gregorian calendar dates and 24-hour-clock times for information interchange."}]},{"slug":"days-between-dates-calculator","title":"Days Between Dates Calculator","url":"https://toolkitshelf.com/tools/days-between-dates-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.days-between-dates-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Start date","End date","Counting method"],"resultLabel":"Days between dates","formula":{"expression":"Days between dates = end date - start date","label":"Days between dates formula","note":"Choose include end date when the final day should count as a full day."},"example":[{"label":"Start date","value":"May 25, 2026"},{"label":"End date","value":"June 24, 2026"},{"label":"Calendar days","value":"30 days"}],"sources":[{"href":"https://www.iso.org/iso-8601-date-and-time-format.html","label":"ISO","value":"ISO 8601 documents Gregorian calendar date representation and time notation used for unambiguous date exchange."}]},{"slug":"business-days-calculator","title":"Business Days Calculator","url":"https://toolkitshelf.com/tools/business-days-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.business-days-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Start date","End date","End date setting","Holiday/PTO days"],"resultLabel":"Adjusted business days","formula":{"expression":"Business days = weekdays between dates - entered holiday/PTO weekdays","label":"Business days formula","note":"Weekdays are Monday through Friday. The calculator does not know exact holiday calendars unless you enter those days as a manual adjustment."},"example":[{"label":"Date range","value":"May 26 to Jun 26"},{"label":"Weekdays","value":"24"},{"label":"Holiday/PTO adjustment","value":"1 day"},{"label":"Adjusted business days","value":"23"}],"sources":[]},{"slug":"add-business-days-calculator","title":"Add Business Days Calculator","url":"https://toolkitshelf.com/tools/add-business-days-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.add-business-days-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Start date","Business days to add","Holiday/closure buffer"],"resultLabel":"Estimated end date","formula":{"expression":"End date = start date + business days, skipping Saturdays and Sundays","label":"Add business days formula","note":"The holiday buffer adds extra weekday padding. It does not model exact holiday dates."},"example":[{"label":"Start date","value":"May 26"},{"label":"Business days","value":"10"},{"label":"Holiday/closure buffer","value":"1 weekday"},{"label":"Estimated end date","value":"About 2 workweeks later"}],"sources":[]},{"slug":"countdown-calculator","title":"Countdown Calculator","url":"https://toolkitshelf.com/tools/countdown-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.countdown-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["From date","Target date"],"resultLabel":"Days until target","formula":{"expression":"Days remaining = target date - from date","label":"Countdown formula","note":"Weeks are days divided by 7. Approximate months use the average month length of 30.4375 days."},"example":[{"label":"From date","value":"Today"},{"label":"Target date","value":"90 days away"},{"label":"Countdown","value":"90 days"},{"label":"Weeks","value":"12.9 weeks"}],"sources":[]},{"slug":"age-calculator","title":"Age Calculator","url":"https://toolkitshelf.com/tools/age-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.age-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Birth date","Current date"],"resultLabel":"Exact age","formula":{"expression":"Age = comparison date - birth date","label":"Age formula","note":"Exact age is shown as full years, remaining months, and remaining days."},"example":[{"label":"Birth date","value":"January 1, 1990"},{"label":"Comparison date","value":"May 25, 2026"},{"label":"Exact age","value":"36 years, 4 months, 24 days"}],"sources":[{"href":"https://www.iso.org/iso-8601-date-and-time-format.html","label":"ISO","value":"ISO 8601 defines a standard ordering for calendar date elements, which helps avoid ambiguous date entry."}]},{"slug":"time-duration-calculator","title":"Time Duration Calculator","url":"https://toolkitshelf.com/tools/time-duration-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.time-duration-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Start time","End time","Break minutes","Hourly rate"],"resultLabel":"Net duration","formula":{"expression":"Net duration = end time - start time - break time","label":"Time duration formula","note":"If the end time is earlier than the start time, the calculator treats it as ending the next day."},"example":[{"label":"Start time","value":"9:00 AM"},{"label":"End time","value":"5:30 PM"},{"label":"Break","value":"30 minutes"},{"label":"Net duration","value":"8h 0m"}],"sources":[{"href":"https://www.nist.gov/time-and-frequency-services/time-and-frequency-z-ti","label":"NIST","value":"Defines time as either the designation of an instant or the interval between two events."}]},{"slug":"timezone-converter","title":"Timezone Converter","url":"https://toolkitshelf.com/tools/timezone-converter","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.timezone-converter","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Date","Time","From timezone","To timezone"],"resultLabel":"Target local time","formula":{"expression":"Converted time = source local date and time resolved to a UTC instant, then formatted in the target IANA time zone","label":"Timezone conversion method","note":"The offset is calculated for the selected date, so daylight saving time changes are reflected in the result."},"example":[{"label":"Source","value":"June 1, 2026 at 9:00 AM in New York"},{"label":"Target","value":"Europe/Stockholm"},{"label":"Result","value":"June 1, 2026 at 3:00 PM in Stockholm"}],"sources":[{"href":"https://www.iana.org/time-zones","label":"IANA Time Zone Database","value":"The IANA time zone database defines regional time zone identifiers and historical offset rules used across software systems."},{"href":"https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/DateTimeFormat","label":"MDN Web Docs","value":"Documents Intl.DateTimeFormat timeZone formatting support for JavaScript applications."}]},{"slug":"timestamp-converter","title":"Unix Timestamp Converter","url":"https://toolkitshelf.com/tools/timestamp-converter","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.timestamp-converter","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Unix timestamp","Timestamp unit","Date","Time","Timezone"],"resultLabel":"Unix timestamp","formula":{"expression":"Unix seconds = milliseconds since 1970-01-01 00:00:00 UTC / 1000","label":"Unix timestamp conversion method","note":"Unix timestamps represent a UTC instant. Timezone only changes the readable display, not the underlying timestamp."},"example":[{"label":"Unix seconds","value":"1772327400"},{"label":"UTC time","value":"2026-03-01T01:10:00.000Z"},{"label":"New York display","value":"February 28, 2026 at 8:10 PM"}],"sources":[{"href":"https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap04.html","label":"The Open Group","value":"Defines Seconds Since the Epoch as a core time representation in POSIX systems."},{"href":"https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date","label":"MDN Web Docs","value":"Documents JavaScript Date time values as milliseconds since the Unix epoch."}]},{"slug":"hours-calculator","title":"Hours Calculator","url":"https://toolkitshelf.com/tools/hours-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.hours-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Hours per day","Days per week","Break minutes","Hourly rate"],"resultLabel":"Net weekly hours","formula":{"expression":"Net weekly hours = hours per day x days per week - daily break hours x days per week","label":"Weekly hours formula","note":"Monthly hours are estimated using 4.333 weeks per month."},"example":[{"label":"Hours per day","value":"8"},{"label":"Days per week","value":"5"},{"label":"Break","value":"30 minutes/day"},{"label":"Net hours","value":"37.5/week"}],"sources":[{"href":"https://www.law.cornell.edu/cfr/text/29/785.18","label":"Legal Information Institute","value":"Reprints 29 CFR 785.18, the federal rule explaining how short rest periods are counted as hours worked."}]},{"slug":"work-hours-calculator","title":"Work Hours Calculator","url":"https://toolkitshelf.com/tools/work-hours-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.work-hours-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Weekday hours","Weekdays worked","Weekend hours","Break minutes","Hourly rate"],"resultLabel":"Weekly work hours","formula":{"expression":"Weekly work hours = weekday hours x weekdays worked + weekend hours - unpaid break hours","label":"Work hours formula","note":"Monthly hours are estimated by multiplying weekly hours by 4.333."},"example":[{"label":"Weekday hours","value":"8"},{"label":"Weekdays","value":"5"},{"label":"Break","value":"30 minutes/day"},{"label":"Weekly hours","value":"37.5"}],"sources":[{"href":"https://www.law.cornell.edu/cfr/text/29/785.18","label":"Legal Information Institute","value":"Reprints 29 CFR 785.18, the federal rule explaining treatment of short rest periods."},{"href":"https://www.law.cornell.edu/uscode/text/29/207","label":"Legal Information Institute","value":"Reprints 29 U.S. Code 207, the federal statute covering maximum hours and overtime compensation."}]},{"slug":"time-card-calculator","title":"Time Card Calculator","url":"https://toolkitshelf.com/tools/time-card-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.time-card-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Start time","End time","Break minutes","Days worked","Hourly rate"],"resultLabel":"Work hours","formula":{"expression":"Daily hours = hours between start and end - break minutes / 60; gross pay = daily hours x days worked x hourly rate","label":"Time card formula","note":"If the end time is earlier than the start time, the calculator treats it as an overnight shift."},"example":[{"label":"Start","value":"9:00 AM"},{"label":"End","value":"5:30 PM"},{"label":"Break","value":"30 minutes"},{"label":"Daily hours","value":"8 hours"}],"sources":[{"href":"https://www.law.cornell.edu/cfr/text/29/785.18","label":"Legal Information Institute","value":"Reprints 29 CFR 785.18, the federal rule explaining how short rest periods are counted as hours worked."},{"href":"https://www.law.cornell.edu/cfr/text/29/778.101","label":"Legal Information Institute","value":"Reprints 29 CFR 778.101, the federal overtime rule for covered nonexempt employees."}]},{"slug":"time-clock-calculator","title":"Time Clock Calculator","url":"https://toolkitshelf.com/tools/time-clock-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.time-clock-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Clock in","Clock out","Break minutes","Days worked","Hourly rate"],"resultLabel":"Net work hours","formula":{"expression":"Net daily hours = hours between clock in and clock out - unpaid break minutes / 60","label":"Time clock formula","note":"If clock-out time is earlier than clock-in time, the calculator treats it as an overnight shift."},"example":[{"label":"Clock in","value":"8:30 AM"},{"label":"Clock out","value":"5:15 PM"},{"label":"Break","value":"45 minutes"},{"label":"Net daily hours","value":"8.00"}],"sources":[{"href":"https://www.law.cornell.edu/cfr/text/29/785.18","label":"Legal Information Institute","value":"Reprints 29 CFR 785.18, the federal rule explaining how short rest periods are counted as hours worked."},{"href":"https://www.law.cornell.edu/cfr/text/29/778.101","label":"Legal Information Institute","value":"Reprints 29 CFR 778.101, the federal overtime rule for covered nonexempt employees."}]},{"slug":"lunch-break-calculator","title":"Lunch Break Calculator","url":"https://toolkitshelf.com/tools/lunch-break-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.lunch-break-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Shift start","Shift end","Lunch start","Lunch end","Hourly rate"],"resultLabel":"Net work time","formula":{"expression":"Net work hours = shift span - lunch duration - other unpaid break minutes / 60","label":"Lunch break formula","note":"Lunch duration is calculated from lunch start and lunch end times."},"example":[{"label":"Shift","value":"9:00 AM - 5:30 PM"},{"label":"Lunch","value":"12:30 PM - 1:00 PM"},{"label":"Other breaks","value":"0 minutes"},{"label":"Net work time","value":"8h 0m"}],"sources":[{"href":"https://www.law.cornell.edu/cfr/text/29/785.18","label":"Legal Information Institute","value":"Reprints 29 CFR 785.18, which explains federal treatment of short rest periods as hours worked."},{"href":"https://www.law.cornell.edu/cfr/text/29/778.101","label":"Legal Information Institute","value":"Reprints 29 CFR 778.101, the federal overtime rule for covered nonexempt employees."}]},{"slug":"grade-calculator","title":"Grade Calculator","url":"https://toolkitshelf.com/tools/grade-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.grade-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Current grade","Desired grade","Final exam weight","Final score"],"resultLabel":"Score needed","formula":{"expression":"Needed final score = (desired grade - current grade x (1 - final weight)) / final weight","label":"Final grade formula","note":"Enter all grades and weights as percentages."},"example":[{"label":"Current grade","value":"86%"},{"label":"Desired grade","value":"90%"},{"label":"Final weight","value":"25%"},{"label":"Needed on final","value":"102%"}],"sources":[{"href":"https://teaching.cornell.edu/teaching-resources/assessment-evaluation/measuring-student-learning","label":"Cornell Center for Teaching Innovation","value":"Explains that summative assessments include systems for calculating individual student grades."},{"href":"https://catalog.registrar.ucla.edu/Policies-and-Regulations/Academic-Policies/Grades","label":"UCLA Registrar","value":"Publishes examples of official grade reporting and grade-point calculation rules."}]},{"slug":"final-grade-calculator","title":"Final Grade Calculator","url":"https://toolkitshelf.com/tools/final-grade-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.final-grade-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Current grade","Desired grade","Final exam weight","Expected final score"],"resultLabel":"Needed on final","formula":{"expression":"Needed final score = (desired grade - current grade x (1 - final weight)) / final weight","label":"Final grade formula","note":"Enter current grade, desired grade, and final exam weight as percentages."},"example":[{"label":"Current grade","value":"86%"},{"label":"Desired grade","value":"90%"},{"label":"Final exam weight","value":"25%"},{"label":"Needed on final","value":"102%"}],"sources":[{"href":"https://teaching.cornell.edu/teaching-resources/assessment-evaluation/measuring-student-learning","label":"Cornell Center for Teaching Innovation","value":"Explains that summative assessments include systems for calculating individual student grades."},{"href":"https://catalog.registrar.ucla.edu/Policies-and-Regulations/Academic-Policies/Grades","label":"UCLA Registrar","value":"Publishes examples of official grade reporting and grade-point calculation rules."}]},{"slug":"weighted-grade-calculator","title":"Weighted Grade Calculator","url":"https://toolkitshelf.com/tools/weighted-grade-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.weighted-grade-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Category scores","Category weights"],"resultLabel":"Weighted grade","formula":{"expression":"Weighted grade = sum(category score x category weight) / sum(category weights)","label":"Weighted grade formula","note":"Enter each category score and weight as percentages. The calculator normalizes when weights do not add to exactly 100%."},"example":[{"label":"Assignments","value":"92% x 30%"},{"label":"Quizzes","value":"84% x 15%"},{"label":"Exams","value":"88% x 35%"},{"label":"Weighted grade","value":"89.4%"}],"sources":[{"href":"https://teaching.cornell.edu/teaching-resources/assessment-evaluation/measuring-student-learning","label":"Cornell Center for Teaching Innovation","value":"Discusses course assessment methods and grade-calculation systems for summative assessment."},{"href":"https://catalog.registrar.ucla.edu/Policies-and-Regulations/Academic-Policies/Grades","label":"UCLA Registrar","value":"Shows institutional grade reporting and grade-point calculation examples."}]},{"slug":"test-grade-calculator","title":"Test Grade Calculator","url":"https://toolkitshelf.com/tools/test-grade-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.test-grade-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Points earned","Points possible","Extra credit","Curve points"],"resultLabel":"Test grade","formula":{"expression":"Test grade = points earned / points possible x 100; adjusted grade can add extra credit and curve points","label":"Test grade formula","note":"Letter grades are approximate because schools and teachers use different scales."},"example":[{"label":"Points earned","value":"42"},{"label":"Points possible","value":"50"},{"label":"Raw grade","value":"84%"},{"label":"Letter estimate","value":"B"}],"sources":[{"href":"https://teaching.cornell.edu/teaching-resources/assessment-evaluation/measuring-student-learning","label":"Cornell Center for Teaching Innovation","value":"Describes tests, quizzes, and other graded activities as summative assessments."},{"href":"https://catalog.registrar.ucla.edu/Policies-and-Regulations/Academic-Policies/Grades","label":"UCLA Registrar","value":"Lists institutional grade categories and grade reporting practices."}]},{"slug":"gpa-calculator","title":"GPA Calculator","url":"https://toolkitshelf.com/tools/gpa-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.gpa-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Class credits","Grade points"],"resultLabel":"Semester GPA","formula":{"expression":"GPA = total quality points / total credits","label":"GPA formula","note":"Quality points are grade points multiplied by credit hours for each class."},"example":[{"label":"Credits","value":"13 total"},{"label":"Quality points","value":"45.1"},{"label":"GPA","value":"3.47"}],"sources":[{"href":"https://catalog.registrar.ucla.edu/Policies-and-Regulations/Academic-Policies/Grades","label":"UCLA Registrar","value":"Explains that GPA is determined by dividing grade points earned by units attempted."},{"href":"https://caac.ucla.edu/policies/grading-repeats/","label":"UCLA College Academic Counseling","value":"Provides GPA calculation instructions using course units, grade points, and total grade points."}]},{"slug":"tip-calculator","title":"Tip Calculator","url":"https://toolkitshelf.com/tools/tip-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.tip-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Bill total","Tip percent","People"],"resultLabel":"Tip and total","formula":{"expression":"Tip = bill total x tip percentage; per person = (bill + tip) / people","label":"Tip formula","note":"Use the bill total after tax if you want to tip on the full receipt amount."},"example":[{"label":"Bill total","value":"$86.40"},{"label":"Tip","value":"20%"},{"label":"Each person pays","value":"$51.84 for 2 people"}],"sources":[]},{"slug":"discount-calculator","title":"Discount Calculator","url":"https://toolkitshelf.com/tools/discount-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.discount-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Original price","Discount percent","Coupon amount","Sales tax"],"resultLabel":"Sale price","formula":{"expression":"Sale price = original price - (original price x discount percent) - coupon amount","label":"Discount formula","note":"Sales tax is estimated after the discount and coupon are applied."},"example":[{"label":"Original price","value":"$120.00"},{"label":"Discount","value":"25%"},{"label":"Sale price","value":"$90.00"}],"sources":[{"href":"https://openstax.org/books/prealgebra-2e/pages/6-2-solve-general-applications-of-percent","label":"OpenStax","value":"Covers percent equations plus percent increase and decrease examples used for discount math."}]},{"slug":"sales-tax-calculator","title":"Sales Tax Calculator","url":"https://toolkitshelf.com/tools/sales-tax-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.sales-tax-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Item price","Sales tax rate","Discount percent"],"resultLabel":"Total after tax","formula":{"expression":"Sales tax = taxable amount x sales tax rate","label":"Sales tax formula","note":"This estimate applies the discount before tax. Local rules can vary."},"example":[{"label":"Item price","value":"$100.00"},{"label":"Sales tax","value":"8.25%"},{"label":"Total","value":"$108.25"}],"sources":[{"href":"https://www.irs.gov/salestax","label":"Internal Revenue Service","value":"Provides a sales tax deduction calculator that uses state and local general sales tax information."},{"href":"https://www.law.cornell.edu/wex/sales_tax","label":"Legal Information Institute","value":"Explains that sales taxes can include state and additional local rates."}]},{"slug":"unit-price-calculator","title":"Unit Price Calculator","url":"https://toolkitshelf.com/tools/unit-price-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.unit-price-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["First price","First quantity","Second price","Second quantity"],"resultLabel":"Unit price","formula":{"expression":"Unit price = package price / number of units","label":"Unit price formula","note":"Use the same unit for both quantities, such as ounces, pounds, pieces, or servings."},"example":[{"label":"First item","value":"$8.99 / 24 units"},{"label":"Second item","value":"$12.49 / 36 units"},{"label":"Better unit price","value":"Second item"}],"sources":[{"href":"https://www.nist.gov/node/1886336","label":"National Institute of Standards and Technology","value":"Publishes a unit pricing guide for making package price comparisons easier and more uniform."}]},{"slug":"price-per-pound-calculator","title":"Price Per Pound Calculator","url":"https://toolkitshelf.com/tools/price-per-pound-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.price-per-pound-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Price","Pounds","Ounces","Comparison package"],"resultLabel":"Price per pound","formula":{"expression":"Price per pound = package price / total pounds","label":"Price per pound formula","note":"Extra ounces are converted to pounds by dividing ounces by 16 before the unit price is calculated."},"example":[{"label":"First package","value":"$6.99 for 1 lb 8 oz"},{"label":"Second package","value":"$9.49 for 2 lb"},{"label":"Better price","value":"First package"}],"sources":[{"href":"https://www.nist.gov/node/1886336","label":"National Institute of Standards and Technology","value":"Publishes unit pricing guidance for comparing packaged goods with a common unit of measure."}]},{"slug":"price-per-ounce-calculator","title":"Price Per Ounce Calculator","url":"https://toolkitshelf.com/tools/price-per-ounce-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.price-per-ounce-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["First price","First ounces","Second price","Second ounces"],"resultLabel":"Price per ounce","formula":{"expression":"Price per ounce = package price / package ounces","label":"Price per ounce formula","note":"Use net ounces for each package. Compare only similar products and usable amounts."},"example":[{"label":"First package","value":"$5.99 / 18 oz"},{"label":"Second package","value":"$8.49 / 28 oz"},{"label":"Better price","value":"Second package"}],"sources":[{"href":"https://www.nist.gov/node/1886336","label":"National Institute of Standards and Technology","value":"Publishes unit pricing guidance for comparing packages by common units of measure."}]},{"slug":"price-per-gram-calculator","title":"Price Per Gram Calculator","url":"https://toolkitshelf.com/tools/price-per-gram-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.price-per-gram-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["First price","First grams","Second price","Second grams"],"resultLabel":"Price per gram","formula":{"expression":"Price per gram = package price / package grams","label":"Price per gram formula","note":"The calculator also shows price per 100g because that is often easier to compare mentally."},"example":[{"label":"First package","value":"$7.99 / 340g"},{"label":"Second package","value":"$11.99 / 500g"},{"label":"Price per 100g","value":"About $2.35 vs $2.40"}],"sources":[{"href":"https://www.nist.gov/node/1886336","label":"National Institute of Standards and Technology","value":"Unit pricing guidance supports comparing products by a uniform unit of measure."}]},{"slug":"price-per-item-calculator","title":"Price Per Item Calculator","url":"https://toolkitshelf.com/tools/price-per-item-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.price-per-item-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Pack price","Item count","Comparison pack"],"resultLabel":"Price per item","formula":{"expression":"Price per item = pack price / item count","label":"Price per item formula","note":"Use the count of usable items, sheets, pods, cans, bars, or pieces in the package."},"example":[{"label":"First pack","value":"$14.99 / 24 items"},{"label":"Second pack","value":"$21.99 / 40 items"},{"label":"Better value","value":"Second pack"}],"sources":[{"href":"https://www.nist.gov/node/1886336","label":"National Institute of Standards and Technology","value":"Unit pricing guidance covers common unit comparisons for packaged consumer goods."}]},{"slug":"cost-per-serving-calculator","title":"Cost Per Serving Calculator","url":"https://toolkitshelf.com/tools/cost-per-serving-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.cost-per-serving-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Package price","Label servings","Servings used","Comparison package"],"resultLabel":"Cost per serving","formula":{"expression":"Cost per serving = package price / number of servings","label":"Cost per serving formula","note":"The usable cost per serving uses the servings you expect to finish, which can be more realistic than the label count."},"example":[{"label":"Package price","value":"$8.99"},{"label":"Label servings","value":"12"},{"label":"Cost per serving","value":"$0.75"}],"sources":[{"href":"https://www.nist.gov/node/1886336","label":"National Institute of Standards and Technology","value":"Unit pricing guidance supports comparing products by a common unit such as serving, ounce, or pound."}]},{"slug":"bulk-buy-calculator","title":"Bulk Buy Calculator","url":"https://toolkitshelf.com/tools/bulk-buy-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.bulk-buy-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Regular unit price","Bulk unit price","Bulk units","Usable percent"],"resultLabel":"Bulk savings","formula":{"expression":"Net savings = regular unit price x usable bulk units - bulk cost - extra costs","label":"Bulk buy formula","note":"Usable bulk units are adjusted for waste, spoilage, storage limits, or items you may not use."},"example":[{"label":"Regular unit price","value":"$0.18"},{"label":"Bulk unit price","value":"$0.13"},{"label":"Usable amount","value":"90%"}],"sources":[{"href":"https://www.nist.gov/node/1886336","label":"National Institute of Standards and Technology","value":"Unit pricing guidance explains how common unit measures make package-size comparisons easier."}]},{"slug":"coupon-savings-calculator","title":"Coupon Savings Calculator","url":"https://toolkitshelf.com/tools/coupon-savings-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.coupon-savings-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Cart subtotal","Percent coupon","Fixed coupon","Sales tax"],"resultLabel":"Coupon savings","formula":{"expression":"Savings = subtotal x coupon percent + fixed coupons + rewards","label":"Coupon savings formula","note":"The calculator caps savings at the subtotal before estimating tax, shipping, and fees."},"example":[{"label":"Cart subtotal","value":"$85.00"},{"label":"Coupon stack","value":"15% + $10 + $5 rewards"},{"label":"Estimated savings","value":"$27.75"}],"sources":[{"href":"https://openstax.org/books/prealgebra-2e/pages/6-2-solve-general-applications-of-percent","label":"OpenStax","value":"Covers percent equations plus percent increase and decrease examples used for discount and coupon math."}]},{"slug":"sale-comparison-calculator","title":"Sale Comparison Calculator","url":"https://toolkitshelf.com/tools/sale-comparison-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.sale-comparison-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Regular prices","Discounts","Coupons","Sales tax"],"resultLabel":"Better deal","formula":{"expression":"Sale total = (regular price x (1 - discount percent) - coupon) x (1 + tax rate)","label":"Sale comparison formula","note":"This calculator applies percentage discount first, then fixed coupon, then estimated sales tax."},"example":[{"label":"First deal","value":"$79, 25% off, $5 coupon"},{"label":"Second deal","value":"$70, 15% off"},{"label":"Better deal","value":"First deal"}],"sources":[{"href":"https://openstax.org/books/prealgebra-2e/pages/6-2-solve-general-applications-of-percent","label":"OpenStax","value":"Explains percent applications used for sale, discount, and savings calculations."}]},{"slug":"bogo-calculator","title":"BOGO Calculator","url":"https://toolkitshelf.com/tools/bogo-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.bogo-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Regular item price","Items received","Items paid for","Coupon"],"resultLabel":"Effective unit price","formula":{"expression":"Effective unit price = (regular price x items paid for - coupon) / items received","label":"BOGO formula","note":"This flexible setup works for BOGO free, buy two get one, and other multi-buy offers."},"example":[{"label":"Regular item price","value":"$12"},{"label":"Offer","value":"2 received, 1 paid for"},{"label":"Effective unit price","value":"$6 before tax"}],"sources":[{"href":"https://openstax.org/books/prealgebra-2e/pages/6-2-solve-general-applications-of-percent","label":"OpenStax","value":"Covers percent applications used for effective discount and savings math."}]},{"slug":"cashback-calculator","title":"Cashback Calculator","url":"https://toolkitshelf.com/tools/cashback-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.cashback-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Purchase amount","Coupon","Cashback rate","Bonus credit"],"resultLabel":"Rewards value","formula":{"expression":"Net cost = checkout total - (discounted subtotal x cashback rate + bonus credit)","label":"Cashback formula","note":"This assumes cashback and bonus credits are worth face value and eventually redeemable."},"example":[{"label":"Purchase","value":"$120"},{"label":"Coupon and cashback","value":"$15 coupon, 5% cashback, $10 credit"},{"label":"Rewards value","value":"About $15.25"}],"sources":[{"href":"https://openstax.org/books/prealgebra-2e/pages/6-2-solve-general-applications-of-percent","label":"OpenStax","value":"Explains percent equations used for cashback rate and discount calculations."}]},{"slug":"grocery-budget-calculator","title":"Grocery Budget Calculator","url":"https://toolkitshelf.com/tools/grocery-budget-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.grocery-budget-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Adults","Teens","Children","Current weekly spend"],"resultLabel":"Monthly grocery target","formula":{"expression":"Monthly target = age-group food plan costs x household-size adjustment","label":"Grocery budget formula","note":"The calculator uses simple planning levels inspired by USDA food plan reporting and separates groceries from restaurant spending."},"example":[{"label":"Household","value":"2 adults, 2 children"},{"label":"Budget level","value":"Moderate"},{"label":"Weekly target","value":"About $292"}],"sources":[{"href":"https://www.fns.usda.gov/cnpp/usda-food-plans-cost-food-monthly-reports","label":"USDA Food and Nutrition Service","value":"Publishes monthly USDA Food Plans reports with food-at-home cost estimates by age, sex, and plan level."}]},{"slug":"grocery-savings-planner","title":"Grocery Savings Planner","url":"https://toolkitshelf.com/tools/grocery-savings-planner","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.grocery-savings-planner","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Current weekly spend","Target weekly spend","Coupon savings","Bulk savings","Waste reduction","Plan length"],"resultLabel":"Grocery savings estimate","formula":{"expression":"Weekly savings = current weekly spend - target weekly spend + coupon savings + monthly bulk savings / 4.333 + current weekly spend x waste reduction %","label":"Grocery savings formula","note":"The estimate keeps food-at-home savings separate from restaurants, delivery, household supplies, and personal care."},"example":[{"label":"Current weekly spend","value":"$225"},{"label":"Target weekly spend","value":"$190"},{"label":"Waste reduction","value":"8%"},{"label":"Weekly savings","value":"About $71"}],"sources":[{"href":"https://www.fns.usda.gov/cnpp/usda-food-plans-cost-food-monthly-reports","label":"USDA Food and Nutrition Service","value":"Publishes monthly USDA Food Plans reports with food-at-home cost estimates by age, sex, and plan level."},{"href":"https://www.nist.gov/node/1886336","label":"National Institute of Standards and Technology","value":"Publishes a unit pricing guide for comparing product prices by common units."}]},{"slug":"grocery-price-book-calculator","title":"Grocery Price Book Calculator","url":"https://toolkitshelf.com/tools/grocery-price-book-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.grocery-price-book-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Regular price","Regular units","Current price","Current units","Best recorded price","Best recorded units","Packages to buy","Units used per week"],"resultLabel":"Grocery buy signal","formula":{"expression":"Unit price = package price / package units; stock-up savings = (regular unit price - current unit price) x total units","label":"Grocery price book formula","note":"Compare only products with similar quality, usable quantity, shelf life, and units."},"example":[{"label":"Regular price","value":"$7.99 / 24 oz"},{"label":"Current price","value":"$5.99 / 24 oz"},{"label":"Best recorded price","value":"$4.99 / 24 oz"},{"label":"Buy signal","value":"Good sale"}],"sources":[{"href":"https://www.nist.gov/node/1886336","label":"NIST","value":"Publishes unit pricing guidance for comparing product prices by common units."},{"href":"https://www.fns.usda.gov/cnpp/usda-food-plans-cost-food-monthly-reports","label":"USDA Food and Nutrition Service","value":"Publishes USDA Food Plans reports with food-at-home cost references for grocery planning."}]},{"slug":"grocery-list-cost-calculator","title":"Grocery List Cost Calculator","url":"https://toolkitshelf.com/tools/grocery-list-cost-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.grocery-list-cost-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Produce","Meat/protein","Pantry","Household items","Coupons"],"resultLabel":"Estimated list total","formula":{"expression":"List total = food categories + household items - coupons","label":"Grocery list formula","note":"Monthly equivalent multiplies the list total by 4.333 weeks."},"example":[{"label":"Food subtotal","value":"$163"},{"label":"Household items","value":"$16"},{"label":"Estimated list total","value":"$171 after coupons"}],"sources":[{"href":"https://www.fns.usda.gov/cnpp/usda-food-plans-cost-food-monthly-reports","label":"USDA Food and Nutrition Service","value":"Publishes USDA Food Plans reports used as food-at-home budgeting references."},{"href":"https://www.bls.gov/cex/","label":"Bureau of Labor Statistics","value":"Consumer Expenditure Surveys track household spending categories for budgeting analysis."}]},{"slug":"meal-cost-calculator","title":"Meal Cost Calculator","url":"https://toolkitshelf.com/tools/meal-cost-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.meal-cost-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Protein cost","Produce cost","Pantry cost","Sauce or spice cost","Packaging or other cost","Servings"],"resultLabel":"Meal cost","formula":{"expression":"Cost per serving = total ingredient cost / servings","label":"Meal cost formula","note":"Total ingredient cost includes the categories you enter, so add only the amounts used in the meal or batch."},"example":[{"label":"Ingredient total","value":"$32.00"},{"label":"Servings","value":"4"},{"label":"Cost per serving","value":"$8.00"}],"sources":[{"href":"https://www.nist.gov/node/1886336","label":"National Institute of Standards and Technology","value":"Unit pricing guidance supports comparing food costs by common units such as serving or weight."}]},{"slug":"pantry-inventory-value-calculator","title":"Pantry Inventory Value Calculator","url":"https://toolkitshelf.com/tools/pantry-inventory-value-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.pantry-inventory-value-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Dry goods","Canned goods","Freezer","Waste risk","Monthly use"],"resultLabel":"Inventory value","formula":{"expression":"Usable value = total replacement value - waste-risk value","label":"Pantry inventory formula","note":"Months covered divides usable value by expected monthly use value."},"example":[{"label":"Inventory value","value":"$550"},{"label":"Waste risk","value":"12%"},{"label":"Months covered","value":"About 3.5 months"}],"sources":[{"href":"https://www.bls.gov/cex/","label":"Bureau of Labor Statistics","value":"Consumer Expenditure Surveys provide household spending context for food and supplies categories."},{"href":"https://www.fns.usda.gov/cnpp/usda-food-plans-cost-food-monthly-reports","label":"USDA Food and Nutrition Service","value":"USDA Food Plans reports provide food-at-home cost references for household grocery planning."}]},{"slug":"household-supplies-budget-calculator","title":"Household Supplies Budget Calculator","url":"https://toolkitshelf.com/tools/household-supplies-budget-calculator","category":"Money Calculators","formulaId":"toolkitshelf.formula.household-supplies-budget-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Paper goods","Cleaning supplies","Laundry","Personal care"],"resultLabel":"Monthly supplies budget","formula":{"expression":"Monthly supplies budget = paper goods + cleaning + laundry + personal care + other supplies","label":"Household supplies formula","note":"The per-person result divides the monthly supplies budget by household size."},"example":[{"label":"Monthly supplies","value":"$190"},{"label":"Household size","value":"4 people"},{"label":"Per person","value":"$47.50/month"}],"sources":[{"href":"https://www.bls.gov/cex/","label":"Bureau of Labor Statistics","value":"Consumer Expenditure Surveys track household spending categories used for budgeting and consumer spending analysis."}]},{"slug":"subscription-cost-calculator","title":"Subscription Cost Calculator","url":"https://toolkitshelf.com/tools/subscription-cost-calculator","category":"Money Calculators","formulaId":"toolkitshelf.formula.subscription-cost-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Streaming monthly","Apps monthly","Annual fees","Unused percent"],"resultLabel":"Monthly subscription cost","formula":{"expression":"Monthly cost = monthly subscriptions + annual fees / 12","label":"Subscription cost formula","note":"Annual cost is the monthly equivalent multiplied by 12. Unused spend is estimated from the annual total."},"example":[{"label":"Monthly subscriptions","value":"$112"},{"label":"Annual fees","value":"$120/year"},{"label":"Annual subscription cost","value":"$1,464"}],"sources":[{"href":"https://www.ftc.gov/news-events/news/press-releases/2024/10/federal-trade-commission-announces-final-click-cancel-rule-making-it-easier-consumers-end-recurring","label":"Federal Trade Commission","value":"Notes consumer issues with recurring subscriptions and negative option programs in its click-to-cancel rulemaking."},{"href":"https://www.bls.gov/cex/","label":"Bureau of Labor Statistics","value":"Consumer Expenditure Surveys track consumer spending categories used in household budget analysis."}]},{"slug":"gas-trip-cost-calculator","title":"Gas Trip Cost Calculator","url":"https://toolkitshelf.com/tools/gas-trip-cost-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.gas-trip-cost-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Trip distance","Miles per gallon","Gas price","People splitting"],"resultLabel":"Gas cost","formula":{"expression":"Gallons needed = distance / MPG; gas cost = gallons needed x gas price; cost per person = gas cost / people","label":"Gas trip cost formula","note":"This is a fuel-only estimate. Tolls, parking, wear, and route changes are not included."},"example":[{"label":"Distance","value":"300 miles"},{"label":"MPG","value":"28"},{"label":"Gas price","value":"$3.65"},{"label":"Fuel cost","value":"$39.11"}],"sources":[{"href":"https://www.fueleconomy.gov/trip/","label":"FuelEconomy.gov","value":"Official U.S. government trip calculator reference for vehicle MPG and trip fuel cost planning."}]},{"slug":"fuel-economy-calculator","title":"Fuel Economy Calculator","url":"https://toolkitshelf.com/tools/fuel-economy-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.fuel-economy-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Miles driven","Gallons used","Gas price","Annual miles"],"resultLabel":"Miles per gallon","formula":{"expression":"MPG = miles driven / gallons used; gallons per 100 miles = gallons used / miles driven x 100","label":"Fuel economy formula","note":"The fuel cost estimate multiplies fuel used by gas price and assumes the same MPG across the annual miles entered."},"example":[{"label":"Miles driven","value":"325"},{"label":"Gallons used","value":"10.5"},{"label":"Fuel economy","value":"30.95 MPG"},{"label":"Cost per mile","value":"$0.118"}],"sources":[{"href":"https://www.epa.gov/fueleconomy","label":"U.S. Environmental Protection Agency","value":"Explains vehicle fuel economy labels and official fuel economy information."},{"href":"https://www.fueleconomy.gov/feg/drive.shtml","label":"FuelEconomy.gov","value":"Explains driving and vehicle factors that can change gas mileage and fuel cost."}]},{"slug":"gas-cost-per-month-calculator","title":"Gas Cost per Month Calculator","url":"https://toolkitshelf.com/tools/gas-cost-per-month-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.gas-cost-per-month-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Monthly miles","Miles per gallon","Gas price","Months"],"resultLabel":"Monthly gas cost","formula":{"expression":"Monthly gas cost = monthly miles / MPG x gas price","label":"Monthly gas cost formula","note":"The estimate assumes the same MPG and gas price across the selected period."},"example":[{"label":"Monthly miles","value":"900"},{"label":"MPG","value":"28"},{"label":"Gas price","value":"$3.65"},{"label":"Monthly gas cost","value":"$117.32"}],"sources":[{"href":"https://www.epa.gov/fueleconomy","label":"U.S. Environmental Protection Agency","value":"Explains official vehicle fuel economy information and labels."},{"href":"https://www.fueleconomy.gov/feg/drive.shtml","label":"FuelEconomy.gov","value":"Explains fuel economy factors and practical fuel-saving driving habits."},{"href":"https://www.fueleconomy.gov/trip/","label":"FuelEconomy.gov","value":"Provides a U.S. government trip calculator reference for MPG and fuel cost planning."}]},{"slug":"commute-cost-calculator","title":"Commute Cost Calculator","url":"https://toolkitshelf.com/tools/commute-cost-calculator","category":"Money Calculators","formulaId":"toolkitshelf.formula.commute-cost-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Round-trip miles","Commute days","Miles per gallon","Gas price","Parking and tolls"],"resultLabel":"Monthly commute cost","formula":{"expression":"Weekly fuel cost = round-trip miles x commute days / MPG x gas price; weekly total = fuel cost + parking and tolls","label":"Commute cost formula","note":"The all-in estimate uses your cost-per-mile input as a broader proxy for vehicle operating cost."},"example":[{"label":"Round-trip commute","value":"28 miles"},{"label":"Schedule","value":"5 days/week"},{"label":"Gas and extras","value":"$58.25/week"},{"label":"Monthly estimate","value":"$252.42"}],"sources":[{"href":"https://www.irs.gov/newsroom/irs-sets-2026-business-standard-mileage-rate-at-725-cents-per-mile-up-25-cents","label":"Internal Revenue Service","value":"Publishes optional standard mileage rates that can be used as a broad cost-per-mile reference."},{"href":"https://www.fueleconomy.gov/feg/drive.shtml","label":"FuelEconomy.gov","value":"Explains driving and vehicle factors that affect fuel economy and commuting fuel cost."}]},{"slug":"parking-cost-calculator","title":"Parking Cost Calculator","url":"https://toolkitshelf.com/tools/parking-cost-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.parking-cost-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Hourly rate","Hours per visit","Visits per month","Monthly pass","Taxes and fees"],"resultLabel":"Monthly parking cost","formula":{"expression":"Monthly parking cost = hourly rate x hours per visit x visits per month x (1 + fees percent)","label":"Parking cost formula","note":"Pass breakeven divides the monthly pass price by the estimated cost per visit."},"example":[{"label":"Hourly rate","value":"$4"},{"label":"Hours per visit","value":"3"},{"label":"Visits/month","value":"12"},{"label":"Monthly cost","value":"About $156 with fees"}],"sources":[]},{"slug":"toll-cost-calculator","title":"Toll Cost Calculator","url":"https://toolkitshelf.com/tools/toll-cost-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.toll-cost-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["One-way toll","Round trips per week","Paid weeks per year","Discount","Monthly fees"],"resultLabel":"Monthly toll cost","formula":{"expression":"Annual toll cost = one-way toll x 2 x round trips per week x paid weeks per year x (1 - discount percent) + monthly fees x 12","label":"Toll cost formula","note":"Use the discount field for transponder, commuter-plan, resident, or account discounts."},"example":[{"label":"One-way toll","value":"$3.50"},{"label":"Round trips/week","value":"5"},{"label":"Discount","value":"15%"},{"label":"Annual estimate","value":"About $1,488 plus fees"}],"sources":[]},{"slug":"download-time-calculator","title":"Download Time Calculator","url":"https://toolkitshelf.com/tools/download-time-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.download-time-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["File size","Internet speed","Network overhead"],"resultLabel":"Estimated download time","formula":{"expression":"Download seconds = file size in gigabytes x 8,192 megabits x overhead factor / Mbps","label":"Download time formula","note":"One gigabyte is approximated as 8,192 megabits. Real downloads may be slower than the advertised connection speed."},"example":[{"label":"File size","value":"10 GB"},{"label":"Speed","value":"100 Mbps"},{"label":"Overhead","value":"10%"},{"label":"Estimated time","value":"About 15 minutes"}],"sources":[]},{"slug":"data-usage-calculator","title":"Data Usage Calculator","url":"https://toolkitshelf.com/tools/data-usage-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.data-usage-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Streaming hours","Video calls","Gaming","Browsing","Plan cap"],"resultLabel":"Monthly data usage","formula":{"expression":"Monthly data = weekly activity GB x 4.345 + daily browsing GB x 30.4375 + other monthly GB","label":"Data usage formula","note":"Streaming is user-entered because video quality changes usage dramatically. Video calls and gaming use simple planning assumptions."},"example":[{"label":"Streaming","value":"14 hr/week at 3 GB/hr"},{"label":"Video calls","value":"8 hr/week"},{"label":"Other use","value":"50 GB/month"},{"label":"Monthly estimate","value":"About 284 GB"}],"sources":[]},{"slug":"electricity-cost-calculator","title":"Electricity Cost Calculator","url":"https://toolkitshelf.com/tools/electricity-cost-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.electricity-cost-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Watts","Hours per day","Days","Electricity rate"],"resultLabel":"Electricity cost","formula":{"expression":"Cost = watts / 1000 x hours per day x days x electricity rate per kWh","label":"Electricity cost formula","note":"Use the wattage listed on the device or a measured average. Actual energy use can vary by setting and duty cycle."},"example":[{"label":"Watts","value":"1,500"},{"label":"Hours/day","value":"3"},{"label":"Rate","value":"18 cents/kWh"},{"label":"30-day cost","value":"$24.30"}],"sources":[{"href":"https://www.eia.gov/energyexplained/electricity/measuring-electricity.php","label":"U.S. Energy Information Administration","value":"Explains watts, watthours, and kilowatt-hours with examples of power used over time."},{"href":"https://www.eia.gov/energyexplained/electricity/prices-and-factors-affecting-prices.php","label":"U.S. Energy Information Administration","value":"Explains electricity prices per kilowatt-hour and why local household rates vary."}]},{"slug":"electricity-bill-calculator","title":"Electricity Bill Calculator","url":"https://toolkitshelf.com/tools/electricity-bill-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.electricity-bill-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Monthly kWh","Cents per kWh","Fixed fee","Taxes","Months"],"resultLabel":"Monthly electricity bill","formula":{"expression":"Bill = monthly kWh x rate per kWh + fixed fees + taxes and surcharges","label":"Electricity bill formula","note":"Some utilities also use delivery charges, tiered rates, demand charges, or time-of-use pricing."},"example":[{"label":"Monthly usage","value":"850 kWh"},{"label":"Energy rate","value":"18 cents/kWh"},{"label":"Fixed fee and taxes","value":"$21.72"},{"label":"Estimated bill","value":"$174.72"}],"sources":[{"href":"https://www.eia.gov/energyexplained/electricity/measuring-electricity.php","label":"U.S. Energy Information Administration","value":"Explains watts, watthours, and kilowatt-hours as common electricity measurement units."},{"href":"https://www.eia.gov/energyexplained/electricity/prices-and-factors-affecting-prices.php","label":"U.S. Energy Information Administration","value":"Explains that electricity prices vary by generation, transmission, distribution, fuel cost, weather, and regulations."}]},{"slug":"appliance-wattage-calculator","title":"Appliance Wattage Calculator","url":"https://toolkitshelf.com/tools/appliance-wattage-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.appliance-wattage-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Watts","Quantity","Hours per day","Days per month","Electricity rate"],"resultLabel":"Appliance energy cost","formula":{"expression":"kWh = watts x quantity x hours / 1000; cost = kWh x electricity rate","label":"Appliance wattage formula","note":"Actual use can be lower than nameplate wattage when appliances cycle on and off."},"example":[{"label":"Watts","value":"1,200"},{"label":"Use","value":"2 hours/day for 30 days"},{"label":"Energy","value":"72 kWh/month"},{"label":"At 18 cents/kWh","value":"$12.96/month"}],"sources":[{"href":"https://www.eia.gov/energyexplained/electricity/prices-and-factors-affecting-prices.php","label":"U.S. Energy Information Administration","value":"Explains electricity prices per kilowatt-hour and why local household rates vary."},{"href":"https://www.eia.gov/energyexplained/electricity/measuring-electricity.php","label":"U.S. Energy Information Administration","value":"Explains watts, watthours, and kilowatt-hours with examples of power used over time."}]},{"slug":"laundry-cost-calculator","title":"Laundry Cost Calculator","url":"https://toolkitshelf.com/tools/laundry-cost-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.laundry-cost-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Loads per week","Washer kWh","Dryer kWh","Water gallons","Utility rates"],"resultLabel":"Laundry cost","formula":{"expression":"Cost per load = washer kWh x electric rate + dryer kWh x electric rate + gallons / 1,000 x water rate + detergent cost","label":"Laundry cost formula","note":"Actual energy and water use vary by machine, cycle, temperature, load size, and drying method."},"example":[{"label":"Loads/week","value":"5"},{"label":"Energy","value":"3.5 kWh/load"},{"label":"Water","value":"25 gal/load"},{"label":"Estimated cost","value":"About $1.28/load"}],"sources":[{"href":"https://www.eia.gov/energyexplained/electricity/measuring-electricity.php","label":"U.S. Energy Information Administration","value":"Explains how watts, hours of use, and kilowatt-hours relate when estimating electricity consumption."},{"href":"https://www.epa.gov/watersense/how-we-use-water","label":"EPA WaterSense","value":"Explains household water use context for estimating water-related utility costs."}]},{"slug":"dishwasher-cost-calculator","title":"Dishwasher Cost Calculator","url":"https://toolkitshelf.com/tools/dishwasher-cost-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.dishwasher-cost-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Cycles per week","kWh per cycle","Gallons per cycle","Utility rates","Detergent cost"],"resultLabel":"Dishwasher cost","formula":{"expression":"Cost per cycle = kWh per cycle x electric rate + gallons / 1,000 x water rate + detergent cost","label":"Dishwasher cost formula","note":"Cycle type, heated dry, water temperature, and appliance efficiency can change the actual cost."},"example":[{"label":"Cycles/week","value":"7"},{"label":"Energy","value":"1.2 kWh/cycle"},{"label":"Water","value":"4 gal/cycle"},{"label":"Estimated cost","value":"About $0.56/cycle"}],"sources":[{"href":"https://www.eia.gov/energyexplained/electricity/measuring-electricity.php","label":"U.S. Energy Information Administration","value":"Explains how watts, hours of use, and kilowatt-hours relate when estimating electricity consumption."},{"href":"https://www.epa.gov/watersense/how-we-use-water","label":"EPA WaterSense","value":"Explains household water use context for estimating water-related utility costs."}]},{"slug":"shower-cost-calculator","title":"Shower Cost Calculator","url":"https://toolkitshelf.com/tools/shower-cost-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.shower-cost-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Minutes per shower","Gallons per minute","Showers per week","Water rate","Heating cost"],"resultLabel":"Shower cost","formula":{"expression":"Cost per shower = minutes x gallons per minute / 1,000 x water rate + hot water heating cost","label":"Shower cost formula","note":"Hot water heating is entered as a user assumption because it varies by fuel, heater efficiency, and temperature settings."},"example":[{"label":"Shower length","value":"10 minutes"},{"label":"Flow rate","value":"2.1 gal/min"},{"label":"Water use","value":"21 gallons"},{"label":"Estimated cost","value":"About $0.50/shower"}],"sources":[{"href":"https://www.epa.gov/watersense/showerheads","label":"EPA WaterSense","value":"Explains standard and WaterSense showerhead flow rates plus shower water-use context."},{"href":"https://www.epa.gov/watersense/how-we-use-water","label":"EPA WaterSense","value":"Explains household water use context for estimating water-related utility costs."}]},{"slug":"water-bill-calculator","title":"Water Bill Calculator","url":"https://toolkitshelf.com/tools/water-bill-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.water-bill-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Monthly gallons","Water rate","Sewer rate","Fixed fee","Months"],"resultLabel":"Monthly water bill","formula":{"expression":"Bill = gallons / 1,000 x water rate + gallons / 1,000 x sewer rate + fixed fee","label":"Water bill formula","note":"Local bills may use tiers, minimums, stormwater fees, taxes, or separate meter charges."},"example":[{"label":"Monthly use","value":"6,000 gallons"},{"label":"Water + sewer rate","value":"$13 per 1,000 gal"},{"label":"Fixed fee","value":"$25"},{"label":"Estimated bill","value":"$103/month"}],"sources":[{"href":"https://www.epa.gov/watersense/how-we-use-water","label":"EPA WaterSense","value":"Explains household water use and notes that outdoor water use can drive seasonal changes."},{"href":"https://www.epa.gov/watersense/home-maintenance","label":"EPA WaterSense","value":"Home maintenance guidance covers leaks and household water-saving checks that can affect usage."}]},{"slug":"natural-gas-bill-calculator","title":"Natural Gas Bill Calculator","url":"https://toolkitshelf.com/tools/natural-gas-bill-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.natural-gas-bill-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Monthly therms","Price per therm","Fixed fee","Taxes","Months"],"resultLabel":"Monthly gas bill","formula":{"expression":"Bill = therms x price per therm + fixed fee + taxes and surcharges","label":"Natural gas bill formula","note":"Some bills convert gas volume to therms using local heat content or billing factors."},"example":[{"label":"Monthly use","value":"55 therms"},{"label":"Rate","value":"$1.45/therm"},{"label":"Fixed fee and taxes","value":"$21.91"},{"label":"Estimated bill","value":"$101.66"}],"sources":[{"href":"https://www.eia.gov/tools/faqs/faq.php?id=45&t=7","label":"U.S. Energy Information Administration","value":"Explains natural gas billing units including Ccf, Mcf, Btu, and therm conversions."}]},{"slug":"trash-bill-calculator","title":"Trash Bill Calculator","url":"https://toolkitshelf.com/tools/trash-bill-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.trash-bill-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Base monthly fee","Pickup fee","Pickups","Extra bags","Taxes and fees"],"resultLabel":"Monthly trash bill","formula":{"expression":"Monthly trash bill = base fee + pickup fee x pickups + extra bags x bag fee + taxes and fees","label":"Trash bill formula","note":"Local bills may include recycling, yard waste, cart rental, fuel surcharges, or municipal fees."},"example":[{"label":"Base fee","value":"$32/month"},{"label":"Pickups","value":"4/month"},{"label":"Extra bags","value":"2/month"},{"label":"Monthly estimate","value":"About $55"}],"sources":[]},{"slug":"utility-bill-split-calculator","title":"Utility Bill Split Calculator","url":"https://toolkitshelf.com/tools/utility-bill-split-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.utility-bill-split-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Electric bill","Water bill","Gas bill","Internet bill","People splitting"],"resultLabel":"Utility split","formula":{"expression":"Equal share = total utilities / people; custom share = total utilities x share percent","label":"Utility bill split formula","note":"Use the actual bill totals for the billing period and agree on whether to split each bill equally or by custom shares."},"example":[{"label":"Total utilities","value":"$435"},{"label":"People","value":"3"},{"label":"Equal share","value":"$145/person"}],"sources":[{"href":"https://www.eia.gov/energyexplained/electricity/prices-and-factors-affecting-prices.php","label":"U.S. Energy Information Administration","value":"Explains electricity prices and factors that can affect electric bills."},{"href":"https://www.epa.gov/watersense/how-we-use-water","label":"EPA WaterSense","value":"Explains household water use and factors that can move water use up or down."}]},{"slug":"internet-bill-split-calculator","title":"Internet Bill Split Calculator","url":"https://toolkitshelf.com/tools/internet-bill-split-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.internet-bill-split-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Plan price","Equipment fee","Taxes and fees","People","Share percent"],"resultLabel":"Internet bill split","formula":{"expression":"Monthly bill = plan price + equipment + taxes and fees; equal share = monthly bill / people","label":"Internet bill split formula","note":"Use the actual billed amount if promotional discounts, equipment fees, or taxes change month to month."},"example":[{"label":"Plan","value":"$70"},{"label":"Equipment and fees","value":"$23"},{"label":"3-way equal split","value":"$31/person"}],"sources":[{"href":"https://docs.fcc.gov/public/attachments/DA-24-459A1_Rcd.pdf","label":"Federal Communications Commission","value":"Broadband consumer label guidance covers monthly price and service-offering disclosures."}]},{"slug":"cleaning-service-cost-calculator","title":"Cleaning Service Cost Calculator","url":"https://toolkitshelf.com/tools/cleaning-service-cost-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.cleaning-service-cost-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Square feet","Hours","Cleaners","Hourly rate","Supplies fee","Tip"],"resultLabel":"Cleaning service cost","formula":{"expression":"Total = hours x cleaners x hourly rate + supplies/travel fee + tip","label":"Cleaning service cost formula","note":"Flat-rate quotes can differ from hourly estimates, especially for deep cleans, move-out cleans, or heavy clutter."},"example":[{"label":"Home size","value":"1,600 sq ft"},{"label":"Labor","value":"2 cleaners x 4 hr x $35"},{"label":"Supplies/travel","value":"$15"},{"label":"Total with tip","value":"About $339"}],"sources":[]},{"slug":"moving-supply-cost-calculator","title":"Moving Supply Cost Calculator","url":"https://toolkitshelf.com/tools/moving-supply-cost-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.moving-supply-cost-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Small boxes","Medium boxes","Large boxes","Wardrobe boxes","Tape","Packing paper","Buffer"],"resultLabel":"Moving supply cost","formula":{"expression":"Supply cost = boxes x unit prices + tape x unit price + packing bundles x unit price + buffer","label":"Moving supply cost formula","note":"The calculator uses built-in planning prices for common moving supplies. Adjust counts to match your move."},"example":[{"label":"Boxes","value":"60 total"},{"label":"Tape","value":"6 rolls"},{"label":"Packing bundles","value":"2"},{"label":"Estimated supply cost","value":"About $236"}],"sources":[]},{"slug":"home-project-cost-planner","title":"Home Project Cost Planner","url":"https://toolkitshelf.com/tools/home-project-cost-planner","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.home-project-cost-planner","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Project budget","Material cost","Labor hours","Labor rate","Tool rental","Delivery fees","Permit fees","Contingency percent","Project square feet"],"resultLabel":"Home project cost estimate","formula":{"expression":"Estimated project cost = materials + labor + tool rental + delivery + permit fees + contingency","label":"Home project cost formula","note":"Labor equals labor hours times labor rate. Contingency is applied to the direct project cost."},"example":[{"label":"Budget","value":"$5,000"},{"label":"Materials","value":"$2,100"},{"label":"Labor","value":"24 hours at $75/hr"},{"label":"Signal","value":"Within budget"}],"sources":[{"href":"https://www.nist.gov/pml/owm/metric-si/unit-conversion/approximate-conversions-us-customary-measures-metric","label":"NIST","value":"Lists square foot as an area unit and provides common U.S. customary conversion factors."}]},{"slug":"square-footage-calculator","title":"Square Footage Calculator","url":"https://toolkitshelf.com/tools/square-footage-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.square-footage-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Feet or meters","Length","Width","Number of spaces","Price per area"],"resultLabel":"Square footage","formula":{"expression":"Area = length x width; total area = area x number of spaces; cost = total area x price per area unit","label":"Square footage formula","note":"Use the same unit for length and width. The calculator supports feet/square feet and meters/square meters for rectangular spaces."},"example":[{"label":"Length","value":"12 ft"},{"label":"Width","value":"10 ft"},{"label":"Area","value":"120 sq ft / 11.15 sq m"},{"label":"At $4.50/sq ft","value":"$540"}],"sources":[{"href":"https://www.nist.gov/pml/owm/metric-si/unit-conversion/approximate-conversions-us-customary-measures-metric","label":"NIST","value":"Lists square foot as an area unit and gives approximate U.S. customary to metric area conversions."}]},{"slug":"paint-calculator","title":"Paint Calculator","url":"https://toolkitshelf.com/tools/paint-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.paint-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Feet or meters","Room perimeter","Wall height","Doors/windows area","Coats","Coverage"],"resultLabel":"Paint needed","formula":{"expression":"Paintable area = perimeter x wall height - doors and windows; gallons = paintable area x coats / coverage per gallon","label":"Paint calculator formula","note":"Coverage varies by paint, surface texture, color change, primer, and application method."},"example":[{"label":"Perimeter","value":"44 ft"},{"label":"Wall height","value":"8 ft"},{"label":"Doors/windows","value":"60 sq ft / 5.57 sq m"},{"label":"Paint needed","value":"1.75 gallons"}],"sources":[{"href":"https://www.sherwin-williams.com/en-us/color/color-tools/paint-calculator","label":"Sherwin-Williams","value":"Paint calculator guidance notes that one gallon typically covers about 350 to 400 square feet, depending on surface and coverage."}]},{"slug":"room-paint-calculator","title":"Room Paint Calculator","url":"https://toolkitshelf.com/tools/room-paint-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.room-paint-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Feet or meters","Room length","Room width","Wall height","Walls","Coverage"],"resultLabel":"Room paint needed","formula":{"expression":"Paintable area = selected wall perimeter x height - doors/windows; gallons = area x coats / coverage","label":"Room paint formula","note":"Use feet/square feet or meters/square meters. Coverage varies by product, surface texture, primer, color change, and application method."},"example":[{"label":"Room","value":"12 ft x 10 ft x 8 ft"},{"label":"Metric equivalent","value":"3.66 m x 3.05 m x 2.44 m"},{"label":"Doors/windows","value":"60 sq ft / 5.57 sq m"},{"label":"Two coats","value":"About 1.67 gallons"},{"label":"Rounded buy amount","value":"1.75 gallons"}],"sources":[{"href":"https://www.sherwin-williams.com/en-us/color/color-tools/paint-calculator","label":"Sherwin-Williams","value":"Paint calculator guidance notes that one gallon typically covers about 350 to 400 square feet, depending on surface and coverage."}]},{"slug":"concrete-calculator","title":"Concrete Calculator","url":"https://toolkitshelf.com/tools/concrete-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.concrete-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Feet or meters","Length","Width","Depth","Waste percent","Price per volume"],"resultLabel":"Concrete volume","formula":{"expression":"Concrete volume = length x width x depth after converting all dimensions to one base unit","label":"Concrete volume formula","note":"Feet mode uses inches and cubic yards; meters mode uses centimeters and cubic meters."},"example":[{"label":"12 ft x 10 ft x 4 in","value":"1.48 yd³ before waste"},{"label":"Metric equivalent","value":"3.66 m x 3.05 m x 10.16 cm"},{"label":"With 10% waste","value":"1.63 yd³ / 1.25 m³"},{"label":"80 lb bags","value":"About 74"}],"sources":[{"href":"https://www.quikrete.com/calculator/main.asp","label":"QUIKRETE","value":"Provides concrete calculator guidance and bag estimates for common concrete mixes."}]},{"slug":"concrete-slab-cost-calculator","title":"Concrete Slab Cost Calculator","url":"https://toolkitshelf.com/tools/concrete-slab-cost-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.concrete-slab-cost-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Feet or meters","Length","Width","Depth","Waste percent","Material and labor rates"],"resultLabel":"Concrete slab cost","formula":{"expression":"Total cost = order volume x concrete price + area x base prep rate + area x labor rate","label":"Concrete slab cost formula","note":"Use feet/inches/cubic yards or meters/centimeters/cubic meters. The calculator converts between systems when switching units."},"example":[{"label":"12 ft x 10 ft x 4 in","value":"1.48 yd³ before waste"},{"label":"Metric equivalent","value":"3.66 m x 3.05 m x 10.16 cm"},{"label":"With 10% waste","value":"1.63 yd³ / 1.25 m³"},{"label":"At $160/yd³ plus prep and labor","value":"About $1,101"}],"sources":[{"href":"https://www.quikrete.com/calculator/main.asp","label":"QUIKRETE","value":"Provides concrete calculator guidance and bag estimates for common concrete mixes."}]},{"slug":"flooring-calculator","title":"Flooring Calculator","url":"https://toolkitshelf.com/tools/flooring-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.flooring-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Feet or meters","Room length","Room width","Waste percent","Box coverage","Price per area"],"resultLabel":"Flooring needed","formula":{"expression":"Flooring to buy = length x width x (1 + waste percent)","label":"Flooring formula","note":"Boxes needed are rounded up because flooring is usually sold in whole boxes."},"example":[{"label":"14 ft x 12 ft room","value":"168 sq ft"},{"label":"Metric equivalent","value":"15.61 sq m"},{"label":"With 10% waste","value":"184.8 sq ft / 17.17 sq m"},{"label":"22 sq ft boxes","value":"9 boxes"}],"sources":[{"href":"https://www.nist.gov/pml/owm/metric-si/unit-conversion/approximate-conversions-us-customary-measures-metric","label":"NIST","value":"Lists square foot as an area unit and gives the approximate square-foot to square-meter conversion."},{"href":"https://rigidmaxfloors.com/how-to-measure-for-luxury-vinyl-plank/","label":"Rigid Max Floors","value":"Flooring measurement guidance recommends adding extra material for cuts, waste, and layout matching."}]},{"slug":"carpet-calculator","title":"Carpet Calculator","url":"https://toolkitshelf.com/tools/carpet-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.carpet-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Feet or meters","Room length","Room width","Waste percent","Carpet price","Pad price"],"resultLabel":"Carpet to order","formula":{"expression":"Order area = length x width x (1 + waste percent)","label":"Carpet formula","note":"Use square-yard pricing with feet or square-meter pricing with meters. Actual ordering can depend on roll width, seams, stairs, and installer layout."},"example":[{"label":"Room","value":"14 ft x 12 ft / 4.27 m x 3.66 m"},{"label":"Waste","value":"10%"},{"label":"Order estimate","value":"20.53 sq yd / 17.16 sq m"}],"sources":[{"href":"https://www.lowes.com/pdf/project-planner.pdf","label":"Lowe's","value":"Flooring project planning guidance uses square footage, product coverage, and a 10% waste factor for material estimates."}]},{"slug":"wallpaper-calculator","title":"Wallpaper Calculator","url":"https://toolkitshelf.com/tools/wallpaper-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.wallpaper-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Feet or meters","Room length","Room width","Wall height","Openings","Roll coverage"],"resultLabel":"Wallpaper rolls","formula":{"expression":"Rolls = ceil(((room perimeter x wall height - openings) x (1 + waste percent)) / roll coverage)","label":"Wallpaper roll formula","note":"Use feet/square feet or meters/square meters. Pattern repeat, trimming, damaged strips, and dye lots can change the number of rolls to buy."},"example":[{"label":"Room","value":"12 ft x 10 ft x 8 ft / 3.66 m x 3.05 m x 2.44 m"},{"label":"Openings","value":"45 sq ft / 4.18 sq m"},{"label":"Rolls","value":"7 rolls at 56 sq ft / 5.2 sq m per roll"}],"sources":[{"href":"https://www.lowes.com/pdf/Step-by-Step-Guide-Wallpaper-Installation.pdf","label":"Lowe's","value":"Wallpaper installation guidance recommends following manufacturer directions and calculating wall square footage before ordering."}]},{"slug":"drywall-calculator","title":"Drywall Calculator","url":"https://toolkitshelf.com/tools/drywall-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.drywall-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Feet or meters","Room length","Room width","Wall height","Sheet size","Ceiling option"],"resultLabel":"Drywall sheets","formula":{"expression":"Sheets = ceil((wall area + optional ceiling area) x (1 + waste percent) / sheet area)","label":"Drywall sheet formula","note":"Openings, sheet layout, local code, fire ratings, moisture resistance, and hanging direction can change the final list."},"example":[{"label":"Room","value":"12 ft x 10 ft x 8 ft / 3.66 m x 3.05 m x 2.44 m"},{"label":"Sheet size","value":"4 x 8 ft"},{"label":"Sheets","value":"17 sheets with 10% waste"}],"sources":[{"href":"https://www.usg.com/en-US/p/product/sheetrock-brand-gypsum-panels-141090","label":"USG","value":"Gypsum panel product guidance lists common panel widths, lengths, and thicknesses used for material estimates."}]},{"slug":"deck-board-calculator","title":"Deck Board Calculator","url":"https://toolkitshelf.com/tools/deck-board-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.deck-board-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Feet or meters","Deck length","Deck width","Board width","Board gap","Board length"],"resultLabel":"Deck boards","formula":{"expression":"Boards = ceil((deck area / ((board face width + gap) / 12)) x (1 + waste percent) / board length)","label":"Deck board formula","note":"Use feet/inches or meters/centimeters. Deck design, joist spacing, diagonal layouts, borders, stairs, and railing are not fully modeled."},"example":[{"label":"Deck","value":"16 ft x 12 ft / 4.88 m x 3.66 m"},{"label":"Board","value":"5.5 in / 13.97 cm face, 16 ft / 4.88 m length"},{"label":"Boards","value":"29 boards with 10% waste"}],"sources":[{"href":"https://www.decks.com/calculators/decking-calculator","label":"Decks.com","value":"Decking material guidance estimates boards, waste, screws, and hidden fasteners from deck dimensions and board choices."}]},{"slug":"paver-calculator","title":"Paver Calculator","url":"https://toolkitshelf.com/tools/paver-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.paver-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Feet or meters","Project length","Project width","Paver size","Base depth","Waste percent"],"resultLabel":"Pavers needed","formula":{"expression":"Pavers = ceil((project area / paver area) x (1 + waste percent))","label":"Paver count formula","note":"Use feet/inches/cubic yards or meters/centimeters/cubic meters. Pattern, edge cuts, joints, compaction, and site conditions can change the order."},"example":[{"label":"Project","value":"16 ft x 12 ft / 4.88 m x 3.66 m"},{"label":"Paver","value":"8 in x 4 in / 20.32 cm x 10.16 cm"},{"label":"Pavers","value":"951 pavers with 10% waste"}],"sources":[{"href":"https://contractor.unilock.com/paver-calculator/","label":"Unilock","value":"Paver planning guidance uses project square footage, paver selection, overage, and base material references for estimates."}]},{"slug":"countertop-calculator","title":"Countertop Calculator","url":"https://toolkitshelf.com/tools/countertop-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.countertop-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Feet or meters","Counter length","Counter depth","Island size","Backsplash","Price per area"],"resultLabel":"Countertop square footage","formula":{"expression":"Order area = (counter area + island area + backsplash area) x (1 + waste percent)","label":"Countertop area formula","note":"Use feet/inches and price per square foot or meters/centimeters and price per square meter. Fabrication, seams, slabs, sink cutouts, and installer measurement can change the final quote."},"example":[{"label":"Counters","value":"14 ft x 25.5 in / 4.27 m x 64.77 cm"},{"label":"Island","value":"5 ft x 36 in / 1.52 m x 91.44 cm"},{"label":"Order area","value":"53.63 sq ft / 4.98 sq m with 10% waste"}],"sources":[{"href":"https://www.lowes.com/pdf/kitchen_countertop_measure_guide.pdf","label":"Lowe's","value":"Countertop measuring guidance notes that countertops are sold by square footage."}]},{"slug":"roofing-shingle-calculator","title":"Roofing Shingle Calculator","url":"https://toolkitshelf.com/tools/roofing-shingle-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.roofing-shingle-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Feet or meters","Roof length","Roof width","Roof sections","Pitch","Bundle coverage"],"resultLabel":"Shingle bundles","formula":{"expression":"Bundles = ceil((length x width x sections x pitch factor x (1 + waste percent)) / bundle coverage)","label":"Roof shingle formula","note":"Use feet/square feet or meters/square meters. Complex roof shapes, hips, valleys, dormers, ridge caps, starter strips, underlayment, and local code are not fully modeled."},"example":[{"label":"Roof","value":"40 ft x 28 ft / 12.19 m x 8.53 m"},{"label":"Pitch","value":"6/12 with 12% waste"},{"label":"Bundles","value":"43 bundles at 33.3 sq ft / 3.09 sq m each"}],"sources":[{"href":"https://www.iko.com/na/blog/how-many-shingles-in-a-bundle/","label":"IKO","value":"Roofing guidance explains that a roofing square is 100 square feet and asphalt-shingle bundle coverage varies by product."},{"href":"https://www.gaf.com/en-us/document-library/documents/productdocuments/residentialroofingdocuments/shinglesdocuments/timberlineroofingshinglesdocuments/architecturalshinglesdocuments/timberlinehdzdocuments/Installation_Instructions__Timberline_HDZ_High_Definition_Lifetime_Shingles_.pdf","label":"GAF","value":"Manufacturer installation instructions show product-specific bundle coverage and roof slope requirements."}]},{"slug":"tile-calculator","title":"Tile Calculator","url":"https://toolkitshelf.com/tools/tile-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.tile-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Square feet or square meters","Tile size","Waste percent","Box coverage","Price per area"],"resultLabel":"Tile needed","formula":{"expression":"Tiles = area x (1 + waste percent) / tile area; boxes = area with waste / box coverage","label":"Tile calculator formula","note":"Use square feet with tile dimensions in inches or square meters with tile dimensions in centimeters."},"example":[{"label":"Area","value":"120 sq ft / 11.15 sq m"},{"label":"Waste","value":"10%"},{"label":"12 in / 30.48 cm square tile","value":"132 tiles"},{"label":"16 sq ft / 1.49 sq m boxes","value":"9 boxes"}],"sources":[{"href":"https://www.nist.gov/pml/owm/metric-si/unit-conversion/approximate-conversions-us-customary-measures-metric","label":"NIST","value":"Lists square foot as an area unit and provides common U.S. customary conversion factors."}]},{"slug":"mulch-calculator","title":"Mulch Calculator","url":"https://toolkitshelf.com/tools/mulch-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.mulch-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Feet or meters","Bed length","Bed width","Depth","Price per volume"],"resultLabel":"Mulch volume","formula":{"expression":"Volume = length x width x depth","label":"Mulch volume formula","note":"Feet mode uses inches and cubic yards; meters mode uses centimeters and cubic meters."},"example":[{"label":"20 ft x 6 ft / 6.1 m x 1.83 m bed","value":"120 sq ft / 11.15 sq m"},{"label":"3 in / 7.62 cm depth","value":"30 cubic ft / 0.85 m³"},{"label":"2 cu ft / 56.6 L bags","value":"15 bags"}],"sources":[{"href":"https://www.epa.gov/watersense/landscaping-tips","label":"EPA WaterSense","value":"Landscaping tips say a mulch depth of about three to four inches gives coverage for most plants and warns excessive mulch can restrict water flow."},{"href":"https://www.epa.gov/recycle/composting-home","label":"EPA","value":"Composting guidance discusses using compost as mulch and keeping it a few inches away from plant stems and tree trunks."}]},{"slug":"mulch-bag-calculator","title":"Mulch Bag Calculator","url":"https://toolkitshelf.com/tools/mulch-bag-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.mulch-bag-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Square feet or square meters","Depth","Bag size","Waste percent","Price per bag"],"resultLabel":"Bags of mulch","formula":{"expression":"Bags = area x depth x (1 + waste percent) / bag volume","label":"Mulch bag formula","note":"Feet mode uses square feet, inches, and cubic-foot bags; meters mode uses square meters, centimeters, and liter bags."},"example":[{"label":"20 ft x 6 ft / 6.1 m x 1.83 m bed","value":"120 sq ft / 11.15 sq m"},{"label":"3 in / 7.62 cm depth","value":"30 cubic ft / 0.85 m³ before waste"},{"label":"2 cu ft / 56.6 L bags","value":"15 bags before waste"}],"sources":[{"href":"https://www.epa.gov/watersense/watersense-labeled-homes-outdoors","label":"EPA WaterSense","value":"Outdoor WaterSense guidance discusses water-smart landscape planning and outdoor water use."}]},{"slug":"gravel-calculator","title":"Gravel Calculator","url":"https://toolkitshelf.com/tools/gravel-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.gravel-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Feet or meters","Length","Width","Depth","Density","Price per mass"],"resultLabel":"Gravel needed","formula":{"expression":"Volume = length x width x depth x (1 + waste percent); mass = volume x density","label":"Gravel formula","note":"Feet mode uses inches, cubic yards, and short tons. Meters mode uses centimeters, cubic meters, and metric tonnes."},"example":[{"label":"20 ft x 6 ft / 6.1 m x 1.83 m area","value":"120 sq ft / 11.15 sq m"},{"label":"3 in / 7.62 cm depth with 10% waste","value":"1.22 yd³ / 0.93 m³"},{"label":"At 1.35 tons/yd³ / 1.6 tonnes/m³","value":"1.65 tons / 1.5 tonnes"}],"sources":[{"href":"https://www.nist.gov/pml/owm/metric-si/unit-conversion/approximate-conversions-us-customary-measures-metric","label":"NIST","value":"Provides common U.S. customary unit conversion references for length, area, and volume."}]},{"slug":"soil-calculator","title":"Soil Calculator","url":"https://toolkitshelf.com/tools/soil-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.soil-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Square feet or square meters","Depth","Waste percent","Bag size","Price per bag"],"resultLabel":"Soil needed","formula":{"expression":"Volume = area x depth x (1 + waste percent); bags = volume / bag size","label":"Soil formula","note":"Use square feet with inches and cubic-foot bags, or square meters with centimeters and liter bags."},"example":[{"label":"Area","value":"100 sq ft / 9.29 sq m"},{"label":"Depth","value":"4 in / 10.16 cm"},{"label":"With 5% extra","value":"35 cu ft / 0.99 m³"},{"label":"1.5 cu ft / 42.48 L bags","value":"24 bags"}],"sources":[{"href":"https://www.nist.gov/pml/owm/metric-si/unit-conversion/approximate-conversions-us-customary-measures-metric","label":"NIST","value":"Provides common U.S. customary unit conversion references for length, area, and volume."},{"href":"https://www.epa.gov/watersense/watersense-labeled-homes-outdoors","label":"EPA WaterSense","value":"Outdoor WaterSense guidance discusses landscape planning and outdoor water use."}]},{"slug":"sod-calculator","title":"Sod Calculator","url":"https://toolkitshelf.com/tools/sod-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.sod-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Square feet or square meters","Waste percent","Roll coverage","Price per area","Delivery"],"resultLabel":"Sod needed","formula":{"expression":"Sod to order = lawn area x (1 + waste percent); rolls = sod to order / roll coverage","label":"Sod formula","note":"Roll coverage varies by supplier, so use the square footage or square meter coverage listed for the sod product."},"example":[{"label":"Lawn area","value":"1,200 sq ft / 111.48 sq m"},{"label":"Waste","value":"7%"},{"label":"Sod to order","value":"1,284 sq ft / 119.29 sq m"},{"label":"10 sq ft / 0.93 sq m rolls","value":"129 rolls"}],"sources":[{"href":"https://www.epa.gov/watersense/watersense-labeled-homes-outdoors","label":"EPA WaterSense","value":"Outdoor WaterSense guidance discusses water-smart landscapes and outdoor water use considerations."},{"href":"https://www.nist.gov/pml/owm/metric-si/unit-conversion/approximate-conversions-us-customary-measures-metric","label":"NIST","value":"Lists square foot as an area unit and provides common U.S. customary conversion references."}]},{"slug":"fence-cost-calculator","title":"Fence Cost Calculator","url":"https://toolkitshelf.com/tools/fence-cost-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.fence-cost-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Feet or meters","Panel width","Post spacing","Cost per unit","Gates"],"resultLabel":"Fence cost","formula":{"expression":"Total cost = fence length x cost per unit + gates x cost per gate","label":"Fence cost formula","note":"The estimate rounds panels and posts up from spacing inputs and adds gate posts separately."},"example":[{"label":"Fence length","value":"150 ft or 45.72 m"},{"label":"Panel width","value":"8 ft or 2.44 m"},{"label":"Panels","value":"19"},{"label":"Estimated total","value":"About $5,500"}],"sources":[{"href":"https://pdf.lowes.com/productdocuments/89dcd302-00ce-4578-ba9d-5bffaefc4b87/15274086.pdf","label":"Lowe's","value":"Fencing planning guidance covers measuring project dimensions and comparing fence materials."}]},{"slug":"fahrenheit-to-celsius-calculator","title":"Fahrenheit to Celsius Calculator","url":"https://toolkitshelf.com/tools/fahrenheit-to-celsius-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.fahrenheit-to-celsius-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Fahrenheit","Celsius"],"resultLabel":"Temperature conversion","formula":{"expression":"Celsius = (Fahrenheit - 32) x 5 / 9; Fahrenheit = Celsius x 9 / 5 + 32","label":"Fahrenheit to Celsius formula","note":"Kelvin is Celsius plus 273.15."},"example":[{"label":"32 Fahrenheit","value":"0 Celsius"},{"label":"68 Fahrenheit","value":"20 Celsius"},{"label":"72 Fahrenheit","value":"22.22 Celsius"},{"label":"100 Celsius","value":"212 Fahrenheit"}],"sources":[{"href":"https://www.nist.gov/pml/owm/si-units-temperature","label":"National Institute of Standards and Technology","value":"Lists exact temperature conversion relationships and common Fahrenheit, Celsius, and Kelvin reference points."}]},{"slug":"unit-converter","title":"Unit Converter","url":"https://toolkitshelf.com/tools/unit-converter","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.unit-converter","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Value","From unit","To unit"],"resultLabel":"Converted value","formula":{"expression":"Converted value = input value x source factor / target factor","label":"Unit conversion formula","note":"Temperature conversions use their own formulas because Fahrenheit, Celsius, and Kelvin have different zero points."},"example":[{"label":"Length","value":"10 feet"},{"label":"Converted to","value":"Meters"},{"label":"Result","value":"3.048 meters"}],"sources":[]},{"slug":"inches-to-centimeters-calculator","title":"Inches to Centimeters Calculator","url":"https://toolkitshelf.com/tools/inches-to-centimeters-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.inches-to-centimeters-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Inches"],"resultLabel":"Centimeters","formula":{"expression":"Centimeters = inches x 2.54","label":"Inches to centimeters formula","note":"One inch is exactly 2.54 centimeters."},"example":[{"label":"1 inch","value":"2.54 cm"},{"label":"12 inches","value":"30.48 cm"},{"label":"72 inches","value":"182.88 cm"}],"sources":[]},{"slug":"pounds-to-kilograms-calculator","title":"Pounds to Kilograms Calculator","url":"https://toolkitshelf.com/tools/pounds-to-kilograms-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.pounds-to-kilograms-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Pounds"],"resultLabel":"Kilograms","formula":{"expression":"Kilograms = pounds x 0.45359237","label":"Pounds to kilograms formula","note":"The calculator rounds the display, but uses the full conversion factor internally."},"example":[{"label":"1 lb","value":"0.454 kg"},{"label":"150 lb","value":"68.039 kg"},{"label":"220 lb","value":"99.79 kg"}],"sources":[]},{"slug":"miles-to-kilometers-calculator","title":"Miles to Kilometers Calculator","url":"https://toolkitshelf.com/tools/miles-to-kilometers-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.miles-to-kilometers-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Miles"],"resultLabel":"Kilometers","formula":{"expression":"Kilometers = miles x 1.609344","label":"Miles to kilometers formula","note":"The displayed result is rounded for readability."},"example":[{"label":"1 mile","value":"1.609 km"},{"label":"5 miles","value":"8.047 km"},{"label":"26.2 miles","value":"42.165 km"}],"sources":[]},{"slug":"cups-to-tablespoons-calculator","title":"Cups to Tablespoons Calculator","url":"https://toolkitshelf.com/tools/cups-to-tablespoons-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.cups-to-tablespoons-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Cups"],"resultLabel":"Tablespoons","formula":{"expression":"Tablespoons = cups x 16","label":"Cups to tablespoons formula","note":"This uses US cups and tablespoons."},"example":[{"label":"1/4 cup","value":"4 tbsp"},{"label":"1/2 cup","value":"8 tbsp"},{"label":"1 cup","value":"16 tbsp"}],"sources":[]},{"slug":"cups-to-grams-calculator","title":"Cups to Grams Calculator","url":"https://toolkitshelf.com/tools/cups-to-grams-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.cups-to-grams-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Cups","Ingredient"],"resultLabel":"Estimated grams","formula":{"expression":"Grams = cups x grams per cup for the selected ingredient","label":"Cups to grams formula","note":"Cups measure volume and grams measure weight, so ingredient density matters."},"example":[{"label":"1 cup flour","value":"About 120 g"},{"label":"1 cup sugar","value":"About 200 g"},{"label":"1 cup butter","value":"About 227 g"}],"sources":[{"href":"https://www.kingarthurbaking.com/learn/ingredient-weight-chart","label":"King Arthur Baking","value":"Publishes an ingredient weight chart used as a reference point for common baking conversions."}]},{"slug":"cooking-conversion-calculator","title":"Cooking Conversion Calculator","url":"https://toolkitshelf.com/tools/cooking-conversion-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.cooking-conversion-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Amount","From unit","To unit","Servings"],"resultLabel":"Converted amount","formula":{"expression":"Converted amount = amount x source factor / target factor","label":"Cooking conversion formula","note":"Volume and weight conversions are separate. For ingredients that vary by density, weighing is more accurate."},"example":[{"label":"Amount","value":"2 cups"},{"label":"Converted to","value":"Milliliters"},{"label":"Result","value":"473.176 ml"}],"sources":[]},{"slug":"recipe-scaler","title":"Recipe Scaler","url":"https://toolkitshelf.com/tools/recipe-scaler","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.recipe-scaler","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Ingredient amount","Original servings","Target servings"],"resultLabel":"Scaled amount","formula":{"expression":"Scaled amount = ingredient amount x target servings / original servings","label":"Recipe scaling formula","note":"Use the same unit as the original ingredient amount, such as cups, tablespoons, grams, or ounces."},"example":[{"label":"Original amount","value":"2 cups"},{"label":"Original servings","value":"4"},{"label":"Target servings","value":"10"},{"label":"Scaled amount","value":"5 cups"}],"sources":[]},{"slug":"mortgage-calculator","title":"Mortgage Calculator","url":"https://toolkitshelf.com/tools/mortgage-calculator","category":"Money Calculators","formulaId":"toolkitshelf.formula.mortgage-calculator","isCallableViaMcp":false,"lastReviewed":"2026-07-13","inputs":["Home price","Down payment %","Interest rate","Loan term years","Property tax / year","Insurance / month","HOA / month"],"resultLabel":"Monthly mortgage payment","formula":{"expression":"Monthly mortgage payment = amortized principal-and-interest payment + property tax / 12 + monthly insurance + monthly HOA","label":"Mortgage payment formula","note":"The calculator also estimates total interest from the principal-and-interest payment over the selected loan term."},"example":[{"label":"Home price","value":"$400,000"},{"label":"Down payment","value":"20%"},{"label":"Rate and term","value":"6.75% for 30 years"},{"label":"Principal and interest","value":"$2,075.51"},{"label":"Monthly payment","value":"$2,565.51"},{"label":"Total interest","value":"About $347k before extra payments"}],"sources":[{"href":"https://files.consumerfinance.gov/f/documents/cfpb_buying-a-house_monthly-payment_worksheet.pdf","label":"Consumer Financial Protection Bureau","value":"Provides a monthly mortgage payment worksheet covering principal, interest, taxes, insurance, and HOA-style housing costs."},{"href":"https://www.consumerfinance.gov/ask-cfpb/how-does-paying-down-a-mortgage-work-en-1943/","label":"Consumer Financial Protection Bureau","value":"Explains how mortgage amortization changes the principal and interest portions of payments over time."}],"provenance":{"calculationClass":"estimate","intendedAudience":"Homebuyers and owners estimating a fixed-rate monthly mortgage payment and amortization from price, down payment, rate, term, taxes, insurance, and HOA dues.","maintainedBy":"Toolkit Shelf","materiallyReviewedAt":"2026-07-13","methodVersion":"toolkitshelf.mortgage-fixed-payment-costs.v1","primarySource":{"href":"https://files.consumerfinance.gov/f/documents/cfpb_buying-a-house_monthly-payment_worksheet.pdf","label":"Consumer Financial Protection Bureau monthly payment worksheet","sourceDate":"Current worksheet; accessed July 13, 2026"},"relianceBoundary":"This is not a lender quote, official loan estimate, approval decision, escrow statement, payoff amount, or complete ownership budget.","sourceCheckedAt":"2026-07-13","sourceFreshness":"The CFPB monthly-payment components were checked on July 13, 2026. The calculator uses only user-entered values and does not fetch rates, taxes, insurance, or HOA data.","validityConditions":"The loan uses a fixed annual rate and equal monthly payments. Property tax, insurance, and HOA remain constant; PMI, closing costs, maintenance, utilities, rate changes, and lender-specific escrow adjustments are excluded unless entered elsewhere."}},{"slug":"mortgage-vs-rent-calculator","title":"Mortgage vs Rent Decision Calculator","url":"https://toolkitshelf.com/tools/mortgage-vs-rent-calculator","category":"Money Calculators","formulaId":"toolkitshelf.formula.mortgage-vs-rent-calculator","isCallableViaMcp":false,"lastReviewed":"2026-07-13","inputs":["Monthly rent","Home price","Down payment %","Mortgage rate","Loan term years","Years staying","Property tax / year","Insurance / month","HOA / month","Maintenance % / year","Closing costs %","Selling costs %","Rent growth % / year","Home appreciation % / year"],"resultLabel":"Rent vs buy comparison","formula":{"expression":"Cost difference = estimated owner net cost - estimated rent cost","label":"Mortgage vs rent formula","note":"Owner net cost equals down payment, closing costs, and ownership payments minus estimated equity after sale. Rent cost sums monthly rent with annual rent growth."},"example":[{"label":"Monthly rent","value":"$2,300"},{"label":"Home price","value":"$420,000"},{"label":"Years staying","value":"5 years"},{"label":"Owner net cost","value":"About $161,471"},{"label":"Estimated rent cost","value":"About $146,532"},{"label":"Decision signal","value":"Renting looks lower"}],"sources":[{"href":"https://www.consumerfinance.gov/owning-a-home/prepare/figure-out-how-much-you-want-to-spend/","label":"Consumer Financial Protection Bureau","value":"Explains that total monthly home payment includes principal, interest, taxes, insurance, mortgage insurance, and HOA fees."},{"href":"https://www.consumerfinance.gov/ask-cfpb/what-costs-come-with-taking-out-a-mortgage-en-153/","label":"Consumer Financial Protection Bureau","value":"Explains mortgage costs and the tradeoff between upfront costs and monthly payments."}],"provenance":{"calculationClass":"estimate","intendedAudience":"People comparing a defined rent scenario with a defined home-purchase scenario over a chosen number of years.","maintainedBy":"Toolkit Shelf","materiallyReviewedAt":"2026-07-13","methodVersion":"toolkitshelf.mortgage-vs-rent-scenario.v1","primarySource":{"href":"https://www.consumerfinance.gov/owning-a-home/prepare/figure-out-how-much-you-want-to-spend/","label":"Consumer Financial Protection Bureau home-budget guidance","sourceDate":"Current guide; accessed July 13, 2026"},"relianceBoundary":"The comparison is not a recommendation to rent or buy, a forecast of home value or rent, a lender decision, a tax analysis, or personalized financial advice.","sourceCheckedAt":"2026-07-13","sourceFreshness":"The CFPB guidance on total ownership costs and budget tradeoffs was checked on July 13, 2026. All market and cost assumptions remain user-entered scenarios.","validityConditions":"The result assumes the entered fixed mortgage rate, stay period, ownership costs, rent growth, appreciation, closing costs, and selling costs. It excludes tax deductions, investment opportunity cost, PMI, major repairs, moving costs, and transaction timing differences."}},{"slug":"mortgage-affordability-calculator","title":"Mortgage Affordability Calculator","url":"https://toolkitshelf.com/tools/mortgage-affordability-calculator","category":"Money Calculators","formulaId":"toolkitshelf.formula.mortgage-affordability-calculator","isCallableViaMcp":false,"lastReviewed":"2026-07-13","inputs":["Annual income","Monthly debts","Down payment","Interest rate","Loan term","Monthly taxes, insurance, HOA","Housing limit","Total debt limit"],"resultLabel":"Affordable home price","formula":{"expression":"Affordable payment = min(gross monthly income x housing limit, gross monthly income x total debt limit - monthly debts); affordable price = loan amount from the remaining principal-and-interest budget + down payment","label":"Mortgage affordability formula","note":"The calculator subtracts estimated monthly property taxes, homeowners or mortgage insurance, and HOA dues before estimating a loan amount from the remaining principal-and-interest budget."},"example":[{"label":"Annual income","value":"$95,000"},{"label":"Existing monthly debts","value":"$650"},{"label":"Monthly ownership costs","value":"$525 for taxes, insurance, and HOA"},{"label":"Payment cap","value":"Lower of housing-limit and total-debt-limit methods"},{"label":"Estimated affordable price","value":"About $360k"},{"label":"Next check","value":"Run the listing through mortgage payment and mortgage-vs-rent"}],"sources":[{"href":"https://www.consumerfinance.gov/ask-cfpb/what-is-a-debt-to-income-ratio-en-1791/","label":"Consumer Financial Protection Bureau","value":"Explains debt-to-income ratio and why monthly debt payments are compared with gross monthly income."},{"href":"https://www.consumerfinance.gov/owning-a-home/prepare/figure-out-how-much-you-want-to-spend/","label":"Consumer Financial Protection Bureau","value":"Homebuyer guidance notes that taxes, insurance, mortgage insurance, and HOA fees can affect monthly housing cost."}],"provenance":{"calculationClass":"estimate","intendedAudience":"Prospective homebuyers testing a housing-budget scenario from income, debts, down payment, rate, term, ownership costs, and self-selected debt-ratio limits.","maintainedBy":"Toolkit Shelf","materiallyReviewedAt":"2026-07-13","methodVersion":"toolkitshelf.mortgage-affordability-budget.v1","primarySource":{"href":"https://www.consumerfinance.gov/owning-a-home/prepare/figure-out-how-much-you-want-to-spend/","label":"Consumer Financial Protection Bureau home-budget guidance","sourceDate":"Current guide; accessed July 13, 2026"},"relianceBoundary":"This is not mortgage preapproval, lender underwriting, a property valuation, an interest-rate quote, or a recommendation that the maximum estimated price is affordable for the household.","sourceCheckedAt":"2026-07-13","sourceFreshness":"The CFPB guidance on total monthly housing costs and maintaining a budget cushion was checked on July 13, 2026. Users supply the rate, costs, and debt-ratio limits.","validityConditions":"The estimate assumes the entered gross income, debts, down payment, fixed rate, term, taxes, insurance, HOA, and front-end and back-end limits are complete. PMI, closing costs, maintenance, reserves, and lender adjustments are not automatically added."}},{"slug":"rent-affordability-calculator","title":"Rent Affordability Calculator","url":"https://toolkitshelf.com/tools/rent-affordability-calculator","category":"Money Calculators","formulaId":"toolkitshelf.formula.rent-affordability-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Monthly income","Debt payments","Savings goal","Utilities","Rent rule"],"resultLabel":"Affordable rent","formula":{"expression":"Affordable rent = lower of income x rent rule percentage, or income minus listed monthly obligations","label":"Rent affordability formula","note":"This is a planning estimate. It does not replace a full household budget."},"example":[{"label":"Monthly income","value":"$5,000"},{"label":"Rent rule","value":"30%"},{"label":"Affordable rent","value":"$1,500"}],"sources":[{"href":"https://www.huduser.gov/portal/publications/affhsg/trends_hsg_cost.html","label":"HUD User","value":"Explains the long-running 30-percent-of-income standard for housing affordability analysis."},{"href":"https://www.hud.gov/helping-americans/public-housing-energy-branch-util","label":"HUD","value":"Notes that rent affordability in assisted housing can include shelter plus reasonable utility costs."}]},{"slug":"rent-split-calculator","title":"Rent Split Calculator","url":"https://toolkitshelf.com/tools/rent-split-calculator","category":"Money Calculators","formulaId":"toolkitshelf.formula.rent-split-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Monthly rent","Utilities","People","Your share","Extra costs"],"resultLabel":"Rent share","formula":{"expression":"Equal share = (rent + utilities) / people; custom share = (rent + utilities) x share percentage + extra costs","label":"Rent split formula","note":"Use equal split for simple roommate setups or custom share when bedrooms, parking, or private bathrooms change the split."},"example":[{"label":"Rent","value":"$2,400"},{"label":"Utilities","value":"$300"},{"label":"People","value":"3"},{"label":"Equal split","value":"$900 each"}],"sources":[{"href":"https://scl.cornell.edu/residential-life/housing/housing-details/living-experience/living-roommate","label":"Cornell University Student & Campus Life","value":"Notes that roommate agreements can help establish communication and boundaries before issues arise."},{"href":"https://www.hud.gov/sites/dfiles/PIH/documents/Utility_Allowance_Final_5.2020.pdf","label":"HUD","value":"Documents how utility allowances can be part of housing cost calculations in HUD rental programs."}]},{"slug":"moving-box-calculator","title":"Moving Box Calculator","url":"https://toolkitshelf.com/tools/moving-box-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.moving-box-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Bedrooms","Bathrooms","Living areas","Kitchen","Storage areas"],"resultLabel":"Moving boxes","formula":{"expression":"Total boxes = room-based small, medium, and large box counts x packing buffer","label":"Moving box estimate","note":"Packing style, books, kitchen items, storage, wardrobes, and decluttering can move the estimate up or down."},"example":[{"label":"2 bed / 2 bath","value":"With kitchen and storage"},{"label":"Packing buffer","value":"15%"},{"label":"Estimated boxes","value":"About 58 boxes"}],"sources":[{"href":"https://www.moving.com/moving-boxes/packing-calculator.asp","label":"Moving.com","value":"Packing calculator guidance uses room and home details to estimate moving boxes and supplies."}]},{"slug":"moving-truck-size-calculator","title":"Moving Truck Size Calculator","url":"https://toolkitshelf.com/tools/moving-truck-size-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.moving-truck-size-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Bedrooms","Living areas","Storage areas","Boxes","Large items","Feet or meters"],"resultLabel":"Recommended truck size","formula":{"expression":"Estimated cubic feet = room-based load estimate + boxes + large items + packing buffer","label":"Moving truck size estimate","note":"The estimate is modeled in cubic feet and can be displayed as cubic meters. Truck capacity and home-size fit vary by rental company, furniture size, and packing density."},"example":[{"label":"Home","value":"2 bedrooms, 2 living areas"},{"label":"Boxes and large items","value":"55 boxes, 4 large items"},{"label":"Estimated load","value":"1,702 cu ft / 48.2 m³"},{"label":"Recommended size","value":"26 ft / 7.9 m truck"}],"sources":[{"href":"https://www.pensketruckrental.com/trucks-and-vans/","label":"Penske Truck Rental","value":"Truck size reference lists common rental truck dimensions, capacities, and home-size comparisons."},{"href":"https://www.nist.gov/pml/owm/metric-si/unit-conversion/approximate-conversions-us-customary-measures-metric","label":"NIST","value":"Provides common U.S. customary to metric conversion references for length and volume."}]},{"slug":"storage-unit-size-calculator","title":"Storage Unit Size Calculator","url":"https://toolkitshelf.com/tools/storage-unit-size-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.storage-unit-size-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Bedrooms","Living areas","Boxes","Large items","Aisle access","Feet or meters"],"resultLabel":"Recommended storage unit","formula":{"expression":"Estimated cubic feet = room load + boxes + large items + storage areas, then multiplied by an access buffer","label":"Storage unit estimate","note":"The estimate is modeled in cubic feet and can be displayed as cubic meters. Actual fit depends on furniture shape, stacking, unit height, disassembly, access needs, and facility dimensions."},"example":[{"label":"Home","value":"2 bedrooms, 2 living areas"},{"label":"Boxes and large items","value":"45 boxes, 5 large items"},{"label":"Estimated load","value":"1,188 cu ft / 33.6 m³"},{"label":"Recommended size","value":"10 x 15 ft / 3 x 4.6 m"}],"sources":[{"href":"https://help.publicstorage.com/rent-a-unit/rental-faqs/choose-a-unit-size","label":"Public Storage","value":"Storage size guidance compares common unit sizes such as 5x10, 10x10, 10x15, and 10x20 with room counts."},{"href":"https://www.nist.gov/pml/owm/metric-si/unit-conversion/approximate-conversions-us-customary-measures-metric","label":"NIST","value":"Provides common U.S. customary to metric conversion references for length and volume."}]},{"slug":"moving-cost-calculator","title":"Moving Cost Calculator","url":"https://toolkitshelf.com/tools/moving-cost-calculator","category":"Money Calculators","formulaId":"toolkitshelf.formula.moving-cost-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Moving hours","Movers","Hourly rate","Truck fee","Miles","Supplies"],"resultLabel":"Estimated moving cost","formula":{"expression":"Total = hours x movers x hourly rate + truck fee + miles x price per mile + supplies","label":"Moving cost formula","note":"This is a planning estimate for local moves and does not replace a written mover quote."},"example":[{"label":"2 movers x 5 hours x $65","value":"$650 labor"},{"label":"Truck and mileage","value":"$142.50"},{"label":"Estimated total","value":"$872.50"}],"sources":[{"href":"https://www.fmcsa.dot.gov/consumer-protection/protect-your-move/how-can-i-avoid-unexpected-moving-costs","label":"FMCSA","value":"Protect Your Move guidance says interstate movers must provide a written estimate of charges."},{"href":"https://www.fmcsa.dot.gov/protect-your-move/select-mover","label":"FMCSA","value":"Mover selection guidance recommends getting a written estimate and checking interstate mover credentials."}]},{"slug":"car-affordability-calculator","title":"Car Affordability Calculator","url":"https://toolkitshelf.com/tools/car-affordability-calculator","category":"Money Calculators","formulaId":"toolkitshelf.formula.car-affordability-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Monthly budget","Insurance and maintenance","Down payment","Trade-in","APR and term"],"resultLabel":"Affordable car price","formula":{"expression":"Affordable loan amount = present value of payment budget; vehicle price = (loan amount + down payment + trade-in - fees) / (1 + sales tax rate)","label":"Car affordability formula","note":"The payment budget is the monthly car budget minus estimated insurance and maintenance."},"example":[{"label":"Monthly budget","value":"$650"},{"label":"Insurance and maintenance","value":"$175"},{"label":"Down payment","value":"$5,000"},{"label":"Affordable price","value":"About $28,800"}],"sources":[{"href":"https://www.consumerfinance.gov/ask-cfpb/what-is-included-in-the-monthly-auto-loan-payment-en-819/","label":"Consumer Financial Protection Bureau","value":"Explains that monthly auto loan payments include principal, interest, and agreed charges in the purchase contract."},{"href":"https://www.consumerfinance.gov/consumer-tools/auto-loans/answers/key-terms/","label":"Consumer Financial Protection Bureau","value":"Defines APR and amortization for auto loans."}]},{"slug":"auto-loan-calculator","title":"Auto Loan Calculator","url":"https://toolkitshelf.com/tools/auto-loan-calculator","category":"Money Calculators","formulaId":"toolkitshelf.formula.auto-loan-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Vehicle price","Down payment","Trade-in value","Sales tax","APR","Term months"],"resultLabel":"Monthly car payment","formula":{"expression":"Payment = loan amount x monthly rate / (1 - (1 + monthly rate)^-months)","label":"Auto loan payment formula","note":"Loan amount includes tax and fees, then subtracts down payment and trade-in value."},"example":[{"label":"Vehicle price","value":"$32,000"},{"label":"Down payment","value":"$4,000"},{"label":"APR and term","value":"6.9% for 60 months"},{"label":"Amount financed","value":"$31,040"},{"label":"Payment","value":"$613.17/month"}],"sources":[{"href":"https://www.consumerfinance.gov/ask-cfpb/how-do-i-compare-auto-loan-offers-what-should-i-look-at-besides-the-monthly-payment-en-753/","label":"Consumer Financial Protection Bureau","value":"Explains how to compare auto loan offers beyond the monthly payment."},{"href":"https://www.consumerfinance.gov/consumer-tools/auto-loans/answers/key-terms/","label":"Consumer Financial Protection Bureau","value":"Defines APR, amount financed, finance charge, and amortization for auto loan comparisons."}]},{"slug":"loan-payment-calculator","title":"Loan Payment Calculator","url":"https://toolkitshelf.com/tools/loan-payment-calculator","category":"Money Calculators","formulaId":"toolkitshelf.formula.loan-payment-calculator","isCallableViaMcp":false,"lastReviewed":"2026-07-13","inputs":["Loan amount","Interest rate","Loan term","Extra payment"],"resultLabel":"Monthly payment","formula":{"expression":"Monthly payment = principal x monthly rate / (1 - (1 + monthly rate)^-months)","label":"Loan payment formula","note":"Extra payments are applied after the required amortized payment to estimate faster payoff and interest savings."},"example":[{"label":"Loan amount","value":"$25,000"},{"label":"Rate and term","value":"7.5% for 5 years"},{"label":"Monthly payment","value":"$500.95"},{"label":"Total interest","value":"$5,056.92"}],"sources":[{"href":"https://www.consumerfinance.gov/ask-cfpb/how-does-paying-down-a-mortgage-work-en-1943/","label":"Consumer Financial Protection Bureau","value":"Explains how amortization shifts monthly payments from mostly interest toward more principal over time."},{"href":"https://www.consumerfinance.gov/ask-cfpb/what-is-a-personal-installment-loan-en-2114/","label":"Consumer Financial Protection Bureau","value":"Explains personal installment loans as fixed payments over a specific period of time."}],"provenance":{"calculationClass":"estimate","intendedAudience":"Borrowers comparing fixed-rate installment-loan payments, payoff time, total interest, and an optional constant extra monthly payment.","maintainedBy":"Toolkit Shelf","materiallyReviewedAt":"2026-07-13","methodVersion":"toolkitshelf.loan-payment-fixed-amortization.v1","primarySource":{"href":"https://www.consumerfinance.gov/ask-cfpb/how-does-paying-down-a-mortgage-work-en-1943/","label":"Consumer Financial Protection Bureau amortization guidance","sourceDate":"Last reviewed May 28, 2024"},"relianceBoundary":"This is not a lender quote, payoff statement, loan agreement, refinancing recommendation, or calculation of variable rates, fees, penalties, or lender-specific payment allocation.","sourceCheckedAt":"2026-07-13","sourceFreshness":"The CFPB explanation of fixed-payment amortization was checked on July 13, 2026. No current lender rate or product term is fetched.","validityConditions":"The calculation assumes a fixed annual rate, monthly compounding, equal scheduled payments, and any extra amount applied monthly to principal. Fees, day-count conventions, payment dates, and variable rates are excluded."}},{"slug":"loan-interest-calculator","title":"Loan Interest Calculator","url":"https://toolkitshelf.com/tools/loan-interest-calculator","category":"Money Calculators","formulaId":"toolkitshelf.formula.loan-interest-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Loan amount","Interest rate","Term years","Extra payment"],"resultLabel":"Total loan interest","formula":{"expression":"Monthly interest = remaining balance x annual rate / 12; total interest = sum of monthly interest charges","label":"Loan interest formula","note":"The calculator uses an amortized monthly payment, then adds each month's interest until the loan is paid off."},"example":[{"label":"Loan amount","value":"$20,000"},{"label":"Rate and term","value":"8% for 5 years"},{"label":"Monthly payment","value":"$405.53"},{"label":"Total interest","value":"$4,331.67"}],"sources":[{"href":"https://www.consumerfinance.gov/consumer-tools/auto-loans/answers/key-terms/","label":"Consumer Financial Protection Bureau","value":"Defines amortization as monthly payments applied partly to principal and partly to finance charge interest."},{"href":"https://www.consumerfinance.gov/ask-cfpb/what-is-a-personal-installment-loan-en-2114/","label":"Consumer Financial Protection Bureau","value":"Explains personal installment loans as fixed payments over a specific period of time."}]},{"slug":"apr-calculator","title":"APR Calculator","url":"https://toolkitshelf.com/tools/apr-calculator","category":"Money Calculators","formulaId":"toolkitshelf.formula.apr-calculator","isCallableViaMcp":false,"lastReviewed":"2026-07-13","inputs":["Loan amount","Loan fees","Monthly payment","Term months"],"resultLabel":"Estimated APR","formula":{"expression":"APR is the annualized rate that makes the payment stream equal the net amount received after fees","label":"APR estimate formula","note":"This calculator uses an iterative present-value estimate for fixed monthly payments."},"example":[{"label":"Loan amount","value":"$10,000"},{"label":"Fees","value":"$500"},{"label":"Payment and term","value":"$320 for 36 months"},{"label":"Estimated APR","value":"About 13%"}],"sources":[{"href":"https://www.consumerfinance.gov/ask-cfpb/what-is-the-difference-between-a-loan-interest-rate-and-the-apr-en-733/","label":"Consumer Financial Protection Bureau","value":"Explains that APR includes interest rate plus additional fees charged with the loan."},{"href":"https://www.consumerfinance.gov/consumer-tools/auto-loans/answers/key-terms/","label":"Consumer Financial Protection Bureau","value":"Defines APR for auto loans as annual borrowing cost including fees."}],"provenance":{"calculationClass":"estimate","intendedAudience":"Borrowers comparing fixed-payment loan scenarios from a loan amount, upfront fees, monthly payment, and whole-month term.","maintainedBy":"Toolkit Shelf","materiallyReviewedAt":"2026-07-13","methodVersion":"toolkitshelf.apr-fixed-payment-irr.v1","primarySource":{"href":"https://www.consumerfinance.gov/ask-cfpb/what-is-the-difference-between-a-loan-interest-rate-and-the-apr-en-733/","label":"Consumer Financial Protection Bureau APR guidance","sourceDate":"Last reviewed January 30, 2024"},"relianceBoundary":"This numerical estimate is not a lender's Truth in Lending disclosure, loan offer, legal determination of finance charges, or substitute for the APR in the signed agreement.","sourceCheckedAt":"2026-07-13","sourceFreshness":"The CFPB distinction between interest rate and APR was checked on July 13, 2026. No lender pricing or current market rate is embedded in the calculator.","validityConditions":"The estimate assumes the entered fees are deducted upfront, payments are equal and monthly, and the term is expressed in whole months. Different fee treatment, payment timing, or irregular cash flows can change APR."}},{"slug":"monthly-interest-calculator","title":"Monthly Interest Calculator","url":"https://toolkitshelf.com/tools/monthly-interest-calculator","category":"Money Calculators","formulaId":"toolkitshelf.formula.monthly-interest-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Balance","APR","Billing days"],"resultLabel":"Monthly interest","formula":{"expression":"Monthly interest = balance x APR / 12; daily interest = balance x APR / 365","label":"Monthly interest formula","note":"The billing-cycle estimate uses a daily periodic rate, which is common for credit card interest estimates."},"example":[{"label":"Balance","value":"$5,000"},{"label":"APR","value":"22.99%"},{"label":"Billing days","value":"30"},{"label":"Monthly interest","value":"$95.79"}],"sources":[{"href":"https://www.consumerfinance.gov/ask-cfpb/how-does-my-credit-card-company-calculate-the-amount-of-interest-i-owe-en-51/","label":"Consumer Financial Protection Bureau","value":"Explains that many credit card companies calculate interest daily based on average daily balance."},{"href":"https://www.consumerfinance.gov/ask-cfpb/what-is-a-daily-periodic-rate-on-a-credit-card-en-46/","label":"Consumer Financial Protection Bureau","value":"Explains daily periodic rate and that it is generally calculated from APR divided by 360 or 365."}]},{"slug":"loan-comparison-calculator","title":"Loan Comparison Calculator","url":"https://toolkitshelf.com/tools/loan-comparison-calculator","category":"Money Calculators","formulaId":"toolkitshelf.formula.loan-comparison-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Loan amount","Option A rate","Option A years","Option B rate","Option B years"],"resultLabel":"Loan comparison","formula":{"expression":"Payment = principal x monthly rate / (1 - (1 + monthly rate)^-months)","label":"Loan comparison formula","note":"The same amortized loan formula is applied to both options."},"example":[{"label":"Loan amount","value":"$25,000"},{"label":"Option A","value":"$500.95/mo, $5,056.92 interest"},{"label":"Option B","value":"$453.12/mo, $7,624.93 interest"},{"label":"Lower payment","value":"Option B"},{"label":"Lower interest","value":"Option A"}],"sources":[{"href":"https://www.consumerfinance.gov/owning-a-home/compare/compare-loan-estimates/","label":"Consumer Financial Protection Bureau","value":"Explains how to compare Loan Estimates by rate, payment, upfront costs, lender credits, and five-year cost."},{"href":"https://www.consumerfinance.gov/ask-cfpb/how-do-i-compare-auto-loan-offers-what-should-i-look-at-besides-the-monthly-payment-en-753/","label":"Consumer Financial Protection Bureau","value":"Notes that auto loan offers should be compared by APR, interest rate, loan length, loan amount, and monthly payment."}]},{"slug":"loan-payoff-calculator","title":"Loan Payoff Calculator","url":"https://toolkitshelf.com/tools/loan-payoff-calculator","category":"Money Calculators","formulaId":"toolkitshelf.formula.loan-payoff-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Loan balance","APR","Monthly payment","Extra payment"],"resultLabel":"Payoff time","formula":{"expression":"Monthly interest = balance x APR / 12; principal paid = payment - monthly interest; repeat until balance reaches zero","label":"Loan payoff formula","note":"This calculator uses monthly compounding and assumes payments are made once per month."},"example":[{"label":"Balance","value":"$12,000"},{"label":"APR","value":"8.5%"},{"label":"Payment","value":"$450/month"},{"label":"Payoff","value":"29 months"}],"sources":[{"href":"https://www.consumerfinance.gov/ask-cfpb/how-does-paying-down-a-mortgage-work-en-1943/","label":"Consumer Financial Protection Bureau","value":"Explains how loan amortization shifts payments from interest toward principal as the balance declines."}]},{"slug":"refinance-calculator","title":"Refinance Calculator","url":"https://toolkitshelf.com/tools/refinance-calculator","category":"Money Calculators","formulaId":"toolkitshelf.formula.refinance-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Loan balance","Current payment","New rate","New term years","Closing costs"],"resultLabel":"Refinance break-even","formula":{"expression":"Break-even months = closing costs / monthly savings","label":"Refinance break-even formula","note":"The new payment is an amortized principal-and-interest estimate. A positive monthly savings is required for a break-even month."},"example":[{"label":"Loan balance","value":"$300,000"},{"label":"Current payment","value":"$2,200"},{"label":"New rate and term","value":"5.75% for 30 years"},{"label":"New payment","value":"$1,750.72"},{"label":"Break-even","value":"14 months"}],"sources":[{"href":"https://www.consumerfinance.gov/language/cfpb-in-english/mortgages-key-terms/","label":"Consumer Financial Protection Bureau","value":"Defines mortgage refinance and warns that lower payments can come from extending the loan term."},{"href":"https://www.consumerfinance.gov/ask-cfpb/what-costs-come-with-taking-out-a-mortgage-en-153/","label":"Consumer Financial Protection Bureau","value":"Explains mortgage costs and the tradeoff between upfront costs and monthly payments."}]},{"slug":"debt-to-income-ratio-calculator","title":"Debt-to-Income Ratio Calculator","url":"https://toolkitshelf.com/tools/debt-to-income-ratio-calculator","category":"Money Calculators","formulaId":"toolkitshelf.formula.debt-to-income-ratio-calculator","isCallableViaMcp":false,"lastReviewed":"2026-07-13","inputs":["Gross monthly income","Current or proposed housing payment","Auto loans","Student loans","Credit cards","Other monthly debts"],"resultLabel":"Debt-to-income ratio","formula":{"expression":"Back-end DTI = total monthly debt payments / gross monthly income x 100","label":"Debt-to-income formula","note":"Front-end DTI uses housing payment only. Back-end DTI includes housing plus other recurring monthly debt payments."},"example":[{"label":"Gross monthly income","value":"$6,500"},{"label":"Front-end DTI","value":"28.5%"},{"label":"Total monthly debts","value":"$2,570"},{"label":"Back-end DTI","value":"39.5%"},{"label":"Gross income after listed debts","value":"$3,930"}],"sources":[{"href":"https://www.consumerfinance.gov/ask-cfpb/what-is-a-debt-to-income-ratio-en-1791/","label":"Consumer Financial Protection Bureau","value":"Defines debt-to-income ratio as monthly debt payments divided by gross monthly income."}],"provenance":{"calculationClass":"estimate","intendedAudience":"Consumers making a planning estimate of front-end and back-end debt-to-income ratios from gross monthly income and recurring monthly debt payments.","maintainedBy":"Toolkit Shelf","materiallyReviewedAt":"2026-07-13","methodVersion":"toolkitshelf.dti-monthly-debt-income.v1","primarySource":{"href":"https://www.consumerfinance.gov/ask-cfpb/what-is-a-debt-to-income-ratio-en-1791/","label":"Consumer Financial Protection Bureau debt-to-income guidance","sourceDate":"Last reviewed August 28, 2023"},"relianceBoundary":"The ratios are not a lender underwriting decision, approval threshold, credit assessment, affordability recommendation, or substitute for the debts and income definitions a lender applies.","sourceCheckedAt":"2026-07-13","sourceFreshness":"The CFPB debt-to-income definition and formula were checked on July 13, 2026. No lender-specific limits or current credit policy are embedded.","validityConditions":"Use gross monthly income and include every recurring monthly debt payment relevant to the comparison. Omissions, variable income, lender adjustments, and different housing-payment definitions can materially change the ratio."}},{"slug":"credit-card-interest-calculator","title":"Credit Card Interest Calculator","url":"https://toolkitshelf.com/tools/credit-card-interest-calculator","category":"Money Calculators","formulaId":"toolkitshelf.formula.credit-card-interest-calculator","isCallableViaMcp":false,"lastReviewed":"2026-07-13","inputs":["Average daily balance","APR","Days in billing cycle","Monthly payment"],"resultLabel":"Estimated credit card interest","formula":{"expression":"Interest = average daily balance x (APR / 365) x days in billing cycle","label":"Credit card interest formula","note":"Actual issuers may calculate balances and grace periods differently, so use statements for official numbers."},"example":[{"label":"Average daily balance","value":"$4,200"},{"label":"APR","value":"24.99%"},{"label":"Estimated interest this cycle","value":"About $86.27"},{"label":"Ending balance after payment","value":"About $4,086.27"},{"label":"Cycle interest rate","value":"About 2.05%"}],"sources":[{"href":"https://www.consumerfinance.gov/ask-cfpb/how-does-my-credit-card-company-calculate-the-amount-of-interest-i-owe-en-51/","label":"Consumer Financial Protection Bureau","value":"Explains that many card issuers calculate interest daily from the average daily balance and daily periodic rate."}],"provenance":{"calculationClass":"estimate","intendedAudience":"Cardholders estimating one billing cycle's interest from an already calculated average daily balance, APR, cycle length, and payment.","maintainedBy":"Toolkit Shelf","materiallyReviewedAt":"2026-07-13","methodVersion":"toolkitshelf.credit-card-average-daily-balance.v1","primarySource":{"href":"https://www.consumerfinance.gov/ask-cfpb/how-does-my-credit-card-company-calculate-the-amount-of-interest-i-owe-en-51/","label":"Consumer Financial Protection Bureau credit-card interest guidance","sourceDate":"Last reviewed January 22, 2024"},"relianceBoundary":"This is not an issuer statement, payoff quote, grace-period determination, or reconstruction of transactions, fees, multiple APR balances, and the issuer's exact daily-balance method.","sourceCheckedAt":"2026-07-13","sourceFreshness":"The CFPB explanation of daily periodic rates and average daily balances was checked on July 13, 2026. The calculator does not fetch issuer terms or account data.","validityConditions":"The entered balance must represent the cycle's average daily balance and the APR must apply to that balance. The estimate assumes APR divided by 365 and excludes new transactions, fees, grace periods, and multiple rate buckets."}},{"slug":"credit-card-payoff-calculator","title":"Credit Card Payoff Calculator","url":"https://toolkitshelf.com/tools/credit-card-payoff-calculator","category":"Money Calculators","formulaId":"toolkitshelf.formula.credit-card-payoff-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Card balance","APR","Monthly payment","Extra payment"],"resultLabel":"Months to pay off","formula":{"expression":"New balance = previous balance + monthly interest - monthly payment","label":"Credit card payoff method","note":"The calculator repeats this monthly balance calculation and flags payments that do not cover monthly interest."},"example":[{"label":"Balance","value":"$5,000"},{"label":"APR","value":"22.9%"},{"label":"Payment","value":"$250/month"},{"label":"Payoff time","value":"26 months"},{"label":"Interest paid","value":"$1,358.22"}],"sources":[{"href":"https://www.consumerfinance.gov/ask-cfpb/how-does-my-credit-card-company-calculate-the-amount-of-interest-i-owe-en-51/","label":"Consumer Financial Protection Bureau","value":"Explains that many card companies calculate interest daily using average daily balance methods."},{"href":"https://www.consumerfinance.gov/ask-cfpb/what-is-a-daily-periodic-rate-on-a-credit-card-en-46/","label":"Consumer Financial Protection Bureau","value":"Defines daily periodic rate and notes that APR is usually divided by 360 or 365 days."}]},{"slug":"debt-snowball-calculator","title":"Debt Snowball Calculator","url":"https://toolkitshelf.com/tools/debt-snowball-calculator","category":"Money Calculators","formulaId":"toolkitshelf.formula.debt-snowball-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Smallest debt","Middle debt","Largest debt","Minimum payments","Extra payment","Average APR"],"resultLabel":"Debt payoff time","formula":{"expression":"New balance = previous balance + monthly interest - monthly payoff budget","label":"Debt snowball payoff method","note":"This simplified estimate uses one average APR across the debt stack and assumes the same monthly payoff budget."},"example":[{"label":"Total debt","value":"$14,400"},{"label":"Monthly payoff budget","value":"$670"},{"label":"Average APR","value":"19.9%"},{"label":"Estimated payoff","value":"27 months"},{"label":"Estimated interest","value":"$3,553.52"}],"sources":[{"href":"https://www.consumerfinance.gov/archive/blog/how-reduce-your-debt/","label":"Consumer Financial Protection Bureau","value":"Compares the smallest-balance snowball method with highest-interest-rate debt repayment and explains the tradeoff."}]},{"slug":"salary-calculator","title":"Salary Calculator","url":"https://toolkitshelf.com/tools/salary-calculator","category":"Money Calculators","formulaId":"toolkitshelf.formula.salary-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Hourly pay","Hours per week","Weeks per year"],"resultLabel":"Annual salary","formula":{"expression":"Annual salary = hourly pay x hours per week x weeks per year","label":"Hourly to salary formula","note":"Take-home pay is estimated by subtracting the tax rate entered in the calculator."},"example":[{"label":"Hourly pay","value":"$25"},{"label":"Schedule","value":"40 hours x 52 weeks"},{"label":"Annual salary","value":"$52,000"}],"sources":[{"href":"https://www.irs.gov/individuals/tax-withholding-estimator","label":"Internal Revenue Service","value":"Provides the Tax Withholding Estimator for checking federal income tax withholding from wages."},{"href":"https://www.dol.gov/general/topic/workhours/overtime","label":"U.S. Department of Labor","value":"Explains federal overtime pay basics for covered nonexempt employees."}]},{"slug":"hourly-to-salary-calculator","title":"Hourly to Salary Calculator","url":"https://toolkitshelf.com/tools/hourly-to-salary-calculator","category":"Money Calculators","formulaId":"toolkitshelf.formula.hourly-to-salary-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Hourly pay","Hours per week","Weeks per year","Days per week"],"resultLabel":"Annual salary","formula":{"expression":"Annual salary = hourly pay x hours per week x weeks per year","label":"Hourly to salary formula","note":"This is a gross pay estimate before taxes, benefits, overtime, and deductions."},"example":[{"label":"Hourly pay","value":"$25"},{"label":"Schedule","value":"40 hours x 52 weeks"},{"label":"Annual salary","value":"$52,000"}],"sources":[{"href":"https://www.dol.gov/general/topic/workhours/overtime","label":"U.S. Department of Labor","value":"Summarizes overtime pay rules and cautions that state laws may provide greater protections."},{"href":"https://www.irs.gov/individuals/tax-withholding-estimator","label":"Internal Revenue Service","value":"Offers an estimator for federal tax withholding once gross wages and paycheck details are known."}]},{"slug":"salary-to-hourly-calculator","title":"Salary to Hourly Calculator","url":"https://toolkitshelf.com/tools/salary-to-hourly-calculator","category":"Money Calculators","formulaId":"toolkitshelf.formula.salary-to-hourly-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Annual salary","Hours per week","Paid weeks","Work days"],"resultLabel":"Hourly equivalent","formula":{"expression":"Hourly rate = annual salary / (hours per week x paid weeks per year)","label":"Salary to hourly formula","note":"The conversion is gross pay before taxes, benefits, retirement contributions, and other deductions."},"example":[{"label":"Annual salary","value":"$65,000"},{"label":"Schedule","value":"40 hours/week, 52 paid weeks"},{"label":"Annual hours","value":"2,080"},{"label":"Hourly equivalent","value":"$31.25"}],"sources":[{"href":"https://ecfr.io/Title-29/Section-778.109","label":"Electronic Code of Federal Regulations","value":"Explains that the regular rate under the Fair Labor Standards Act is an hourly rate."},{"href":"https://www.irs.gov/individuals/tax-withholding-estimator","label":"Internal Revenue Service","value":"Provides the Tax Withholding Estimator for checking paycheck withholding after gross pay is known."}]},{"slug":"pay-raise-calculator","title":"Pay Raise Calculator","url":"https://toolkitshelf.com/tools/pay-raise-calculator","category":"Money Calculators","formulaId":"toolkitshelf.formula.pay-raise-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Current pay","Raise percent","Additional annual amount","Hours per week"],"resultLabel":"New pay","formula":{"expression":"New annual pay = annualized current pay + current pay x raise percent + extra annual amount","label":"Pay raise formula","note":"The calculator annualizes hourly pay using hours per week and 52 weeks."},"example":[{"label":"Current salary","value":"$65,000"},{"label":"Raise","value":"5%"},{"label":"New annual pay","value":"$68,250"}],"sources":[{"href":"https://www.bls.gov/eci/","label":"U.S. Bureau of Labor Statistics","value":"Explains how the Employment Cost Index measures changes in wages, salaries, and employer compensation over time."}]},{"slug":"paycheck-calculator","title":"Paycheck Calculator","url":"https://toolkitshelf.com/tools/paycheck-calculator","category":"Money Calculators","formulaId":"toolkitshelf.formula.paycheck-calculator","isCallableViaMcp":false,"lastReviewed":"2026-07-13","inputs":["Hourly rate","Regular hours / week","Overtime hours / week","Estimated tax rate","Pay frequency"],"resultLabel":"Gross paycheck","formula":{"expression":"Gross paycheck = annual gross pay / pay periods; take-home = gross x (1 - tax rate)","label":"Paycheck formula","note":"This is a rough estimate and does not replace payroll or tax withholding calculations."},"example":[{"label":"Hourly rate","value":"$28"},{"label":"Schedule","value":"40 hours/week"},{"label":"Pay frequency","value":"Biweekly"},{"label":"Gross paycheck","value":"$2,240"},{"label":"Estimated take-home","value":"$1,747.20"},{"label":"Annual gross pay","value":"$58,240"}],"sources":[{"href":"https://www.irs.gov/individuals/tax-withholding-estimator","label":"Internal Revenue Service","value":"Provides the Tax Withholding Estimator for checking federal income tax withholding from paychecks."},{"href":"https://www.dol.gov/agencies/whd/overtime","label":"U.S. Department of Labor","value":"Explains the federal overtime pay standard for covered nonexempt employees."}],"provenance":{"calculationClass":"estimate","intendedAudience":"Hourly workers comparing a rough gross-pay and take-home scenario from regular hours, overtime hours, pay frequency, and a self-selected tax rate.","maintainedBy":"Toolkit Shelf","materiallyReviewedAt":"2026-07-13","methodVersion":"toolkitshelf.paycheck-user-rate.v1","primarySource":{"href":"https://www.irs.gov/individuals/tax-withholding-estimator","label":"IRS Tax Withholding Estimator","sourceDate":"Current estimator; accessed July 13, 2026"},"relianceBoundary":"This is not payroll processing, a withholding calculation, a wage-law determination, a pay stub, or a substitute for employer payroll records and the IRS estimator.","sourceCheckedAt":"2026-07-13","sourceFreshness":"The IRS withholding-estimator scope was checked on July 13, 2026. Toolkit Shelf does not embed tax tables; the user supplies one estimated tax rate.","validityConditions":"The estimate assumes 52 identical workweeks, overtime paid at 1.5 times the entered hourly rate, and one effective tax rate applied to gross pay. It excludes benefit deductions, payroll-tax details, state and local rules, exemptions, bonuses, and irregular schedules."}},{"slug":"biweekly-paycheck-calculator","title":"Biweekly Paycheck Calculator","url":"https://toolkitshelf.com/tools/biweekly-paycheck-calculator","category":"Money Calculators","formulaId":"toolkitshelf.formula.biweekly-paycheck-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Annual salary","Pre-tax deductions","Post-tax deductions","Estimated tax rate"],"resultLabel":"Biweekly take-home pay","formula":{"expression":"Gross biweekly pay = annual salary / 26; take-home = gross - pre-tax deductions - estimated tax - post-tax deductions","label":"Biweekly paycheck formula","note":"This is a planning estimate. Payroll withholding depends on forms, benefits, local taxes, and employer rules."},"example":[{"label":"Salary","value":"$65,000"},{"label":"Gross biweekly","value":"$2,500"},{"label":"Tax rate","value":"24%"},{"label":"Estimated take-home","value":"$1,746"}],"sources":[{"href":"https://www.irs.gov/individuals/tax-withholding-estimator","label":"Internal Revenue Service","value":"Provides the Tax Withholding Estimator for checking paycheck withholding assumptions."},{"href":"https://www.irs.gov/filing/federal-income-tax-rates-and-brackets","label":"Internal Revenue Service","value":"Explains federal income tax brackets and why tax is paid in layers, not one rate on all income."}]},{"slug":"salary-paycheck-calculator","title":"Salary Paycheck Calculator","url":"https://toolkitshelf.com/tools/salary-paycheck-calculator","category":"Money Calculators","formulaId":"toolkitshelf.formula.salary-paycheck-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Annual salary","Pay frequency","Pre-tax deductions","Post-tax deductions","Estimated tax rate"],"resultLabel":"Salary paycheck","formula":{"expression":"Gross paycheck = annual salary / pay periods; take-home = gross - pre-tax deductions - estimated tax - post-tax deductions","label":"Salary paycheck formula","note":"This rough estimate does not replace an employer payroll calculator or tax withholding worksheet."},"example":[{"label":"Salary","value":"$75,000"},{"label":"Frequency","value":"Biweekly"},{"label":"Gross paycheck","value":"$2,884.62"},{"label":"Estimated take-home","value":"$1,941.92"}],"sources":[{"href":"https://www.irs.gov/individuals/tax-withholding-estimator","label":"Internal Revenue Service","value":"Provides the Tax Withholding Estimator for paycheck withholding checks."},{"href":"https://www.irs.gov/individuals/employees/tax-withholding","label":"Internal Revenue Service","value":"Explains tax withholding for employees and points workers to the withholding estimator."}]},{"slug":"overtime-calculator","title":"Overtime Calculator","url":"https://toolkitshelf.com/tools/overtime-calculator","category":"Money Calculators","formulaId":"toolkitshelf.formula.overtime-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Hourly rate","Regular hours","Overtime hours","Multiplier"],"resultLabel":"Overtime pay","formula":{"expression":"Overtime pay = hourly rate x overtime multiplier x overtime hours; gross pay = regular pay + overtime pay","label":"Overtime pay formula","note":"A common overtime multiplier is 1.5 for time-and-a-half, but rules vary by location, employer, and worker classification."},"example":[{"label":"Hourly rate","value":"$22"},{"label":"Regular hours","value":"40"},{"label":"Overtime hours","value":"8"},{"label":"Overtime pay","value":"$264"}],"sources":[{"href":"https://www.law.cornell.edu/cfr/text/29/778.101","label":"Legal Information Institute","value":"Reprints 29 CFR 778.101, which summarizes the federal overtime pay standard for covered nonexempt employees."},{"href":"https://www.law.cornell.edu/uscode/text/29/207","label":"Legal Information Institute","value":"Reprints 29 U.S. Code 207, the federal statute covering maximum hours and overtime compensation."}]},{"slug":"double-time-calculator","title":"Double Time Calculator","url":"https://toolkitshelf.com/tools/double-time-calculator","category":"Money Calculators","formulaId":"toolkitshelf.formula.double-time-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Hourly rate","Regular hours","Time-and-a-half hours","Double-time hours"],"resultLabel":"Double-time pay","formula":{"expression":"Gross pay = regular hours x rate + overtime hours x rate x 1.5 + double-time hours x rate x 2","label":"Double-time pay formula","note":"Double-time eligibility depends on location, employer policy, contract rules, and worker classification."},"example":[{"label":"Hourly rate","value":"$24"},{"label":"Regular hours","value":"40"},{"label":"Double-time hours","value":"6"},{"label":"Double-time pay","value":"$288"}],"sources":[{"href":"https://www.law.cornell.edu/cfr/text/29/778.308","label":"Legal Information Institute","value":"Reprints 29 CFR 778.308, which discusses overtime rates including multiples such as double time."},{"href":"https://www.law.cornell.edu/cfr/text/29/778.101","label":"Legal Information Institute","value":"Reprints 29 CFR 778.101, the federal overtime pay standard for covered nonexempt employees."}]},{"slug":"shift-differential-calculator","title":"Shift Differential Calculator","url":"https://toolkitshelf.com/tools/shift-differential-calculator","category":"Money Calculators","formulaId":"toolkitshelf.formula.shift-differential-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Base hourly rate","Standard hours","Differential hours","Differential premium"],"resultLabel":"Shift differential pay","formula":{"expression":"Gross pay = base rate x total hours + differential hours x differential premium","label":"Shift differential formula","note":"Some payroll systems include differential pay when calculating overtime regular rate, so verify against local rules and employer policy."},"example":[{"label":"Base rate","value":"$22/hr"},{"label":"Standard hours","value":"32"},{"label":"Differential hours","value":"8"},{"label":"Differential pay","value":"$20"}],"sources":[{"href":"https://www.law.cornell.edu/cfr/text/29/778.109","label":"Legal Information Institute","value":"Reprints 29 CFR 778.109, which explains that the regular rate is an hourly rate for overtime calculation."},{"href":"https://www.law.cornell.edu/cfr/text/29/778.101","label":"Legal Information Institute","value":"Reprints 29 CFR 778.101, the federal overtime pay standard for covered nonexempt employees."}]},{"slug":"pto-calculator","title":"PTO Calculator","url":"https://toolkitshelf.com/tools/pto-calculator","category":"Money Calculators","formulaId":"toolkitshelf.formula.pto-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["PTO hours per pay period","Pay periods per year","Starting balance","Planned PTO"],"resultLabel":"PTO balance","formula":{"expression":"Available PTO = starting balance + PTO per pay period x pay periods - planned PTO use","label":"PTO accrual formula","note":"The calculator converts hours to days using your entered hours per PTO day."},"example":[{"label":"PTO per pay period","value":"4 hours"},{"label":"Pay periods","value":"26"},{"label":"Annual PTO","value":"104 hours"}],"sources":[{"href":"https://www.dol.gov/general/topic/benefits-leave/vacation_leave?lang=en","label":"U.S. Department of Labor","value":"Explains that federal law generally leaves paid vacation benefits to the agreement between an employer and employee."}]},{"slug":"tax-estimate-calculator","title":"Tax Estimate Calculator","url":"https://toolkitshelf.com/tools/tax-estimate-calculator","category":"Money Calculators","formulaId":"toolkitshelf.formula.tax-estimate-calculator","isCallableViaMcp":false,"lastReviewed":"2026-07-13","inputs":["Annual income","Deductions","Estimated tax rate","Tax credits","Tax withheld"],"resultLabel":"Estimated tax","formula":{"expression":"Estimated tax = max(0, (income - deductions) x tax rate - credits)","label":"Tax estimate formula","note":"This is a simplified planning estimate based on the tax rate you enter, not a full tax filing calculation."},"example":[{"label":"Annual income","value":"$85,000"},{"label":"2026 single-filer standard deduction","value":"$16,100"},{"label":"Taxable income","value":"$68,900"},{"label":"Estimated tax rate","value":"22%"},{"label":"Estimated tax","value":"$15,158"},{"label":"Estimated amount due","value":"$4,158"},{"label":"Effective tax rate","value":"17.8%"}],"sources":[{"href":"https://www.irs.gov/newsroom/irs-releases-tax-inflation-adjustments-for-tax-year-2026-including-amendments-from-the-one-big-beautiful-bill","label":"Internal Revenue Service - tax year 2026 adjustments","value":"Lists the 2026 standard deduction amounts, including $16,100 for single filers."},{"href":"https://www.irs.gov/filing/federal-income-tax-rates-and-brackets","label":"Internal Revenue Service","value":"Explains federal income tax rates and brackets."},{"href":"https://www.irs.gov/individuals/tax-withholding-estimator","label":"Internal Revenue Service","value":"Provides the Tax Withholding Estimator for federal withholding planning."}],"provenance":{"calculationClass":"estimate","intendedAudience":"People testing a simplified annual tax scenario from income, deductions, one self-selected effective tax rate, credits, and withholding.","maintainedBy":"Toolkit Shelf","materiallyReviewedAt":"2026-07-13","methodVersion":"toolkitshelf.tax-user-rate-planning.v1","primarySource":{"href":"https://www.irs.gov/newsroom/irs-releases-tax-inflation-adjustments-for-tax-year-2026-including-amendments-from-the-one-big-beautiful-bill","label":"IRS tax year 2026 inflation adjustments","sourceDate":"Tax year 2026; accessed July 13, 2026"},"relianceBoundary":"This is not a tax return, filing calculation, withholding instruction, bracket calculator, eligibility determination, or substitute for current tax forms and qualified tax advice.","sourceCheckedAt":"2026-07-13","sourceFreshness":"The IRS 2026 standard deduction amounts were checked on July 13, 2026. The calculator uses the single-filer amount only as its editable starting value, embeds no bracket table, and applies the rate entered by the user.","validityConditions":"The estimate subtracts entered deductions, applies one flat rate to the remainder, subtracts entered credits, and compares entered withholding. It does not model progressive brackets, filing status, payroll taxes, state or local tax, credit phaseouts, alternative taxes, or tax-year changes."}},{"slug":"budget-calculator","title":"Budget Calculator","url":"https://toolkitshelf.com/tools/budget-calculator","category":"Money Calculators","formulaId":"toolkitshelf.formula.budget-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Monthly income","Housing","Food","Transportation","Debt","Savings","Other spending"],"resultLabel":"Money left","formula":{"expression":"Money left = monthly income - listed monthly allocations","label":"Budget formula","note":"Savings is treated as an allocation so you can see whether the full plan fits income."},"example":[{"label":"Monthly income","value":"$5,000"},{"label":"Total allocated","value":"$4,250"},{"label":"Money left","value":"$750"}],"sources":[{"href":"https://www.consumerfinance.gov/owning-a-home/prepare/assess-your-spending/","label":"Consumer Financial Protection Bureau","value":"Recommends drawing up a realistic monthly budget and including savings contributions in spending analysis."},{"href":"https://files.consumerfinance.gov/f/documents/cfpb_well-being_monthly-budget.pdf","label":"Consumer Financial Protection Bureau","value":"Provides a monthly budget worksheet for comparing income with expenses and money left over."}]},{"slug":"net-worth-calculator","title":"Net Worth Calculator","url":"https://toolkitshelf.com/tools/net-worth-calculator","category":"Money Calculators","formulaId":"toolkitshelf.formula.net-worth-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Cash","Investments","Home value","Other assets","Mortgage","Student loans","Credit cards","Other debts"],"resultLabel":"Net worth","formula":{"expression":"Net worth = total assets - total liabilities","label":"Net worth formula","note":"Assets are what you own. Liabilities are what you owe."},"example":[{"label":"Total assets","value":"$445,000"},{"label":"Total liabilities","value":"$315,500"},{"label":"Net worth","value":"$129,500"}],"sources":[{"href":"https://www.investor.gov/introduction-investing/investing-basics/save-and-invest/figure-out-your-finances","label":"Investor.gov","value":"Defines a net worth statement as what you own minus liabilities and recommends updating it to track progress."}]},{"slug":"emergency-fund-calculator","title":"Emergency Fund Calculator","url":"https://toolkitshelf.com/tools/emergency-fund-calculator","category":"Money Calculators","formulaId":"toolkitshelf.formula.emergency-fund-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Monthly expenses","Target months","Current savings","Monthly contribution"],"resultLabel":"Emergency fund target","formula":{"expression":"Emergency fund target = monthly expenses x target months","label":"Emergency fund formula","note":"The time-to-target estimate divides the remaining savings gap by the monthly contribution."},"example":[{"label":"Monthly expenses","value":"$4,200"},{"label":"Target months","value":"6"},{"label":"Emergency fund target","value":"$25,200"}],"sources":[{"href":"https://www.consumerfinance.gov/an-essential-guide-to-building-an-emergency-fund/","label":"Consumer Financial Protection Bureau","value":"Explains what emergency funds are, why they matter, how to build them, and where to keep them."},{"href":"https://www.fdic.gov/consumer-resource-center/deposit-accounts","label":"FDIC","value":"Describes savings accounts as deposit accounts used to set aside money for the future."}]},{"slug":"savings-goal-calculator","title":"Savings Goal Calculator","url":"https://toolkitshelf.com/tools/savings-goal-calculator","category":"Money Calculators","formulaId":"toolkitshelf.formula.savings-goal-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Savings goal","Current savings","Monthly contribution","Annual return","Target months"],"resultLabel":"Time to goal","formula":{"expression":"Future balance = current savings x (1 + r)^n + monthly contribution x (((1 + r)^n - 1) / r)","label":"Savings goal formula","note":"The calculator also solves for the monthly contribution required by the target month."},"example":[{"label":"Savings goal","value":"$25,000"},{"label":"Current savings","value":"$5,000"},{"label":"Monthly contribution","value":"$600"},{"label":"Time to goal","value":"31 months"},{"label":"Target-month requirement","value":"$809/month for 24 months"}],"sources":[{"href":"https://www.investor.gov/tools","label":"Investor.gov","value":"Lists free financial planning tools, including compound interest and savings goal calculators."},{"href":"https://consumer.gov/your-money/making-budget","label":"Consumer.gov","value":"Explains that a budget can help save for goals or emergencies."}]},{"slug":"savings-interest-calculator","title":"Savings Interest Calculator","url":"https://toolkitshelf.com/tools/savings-interest-calculator","category":"Money Calculators","formulaId":"toolkitshelf.formula.savings-interest-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Starting balance","Monthly deposit","APY","Years"],"resultLabel":"Future savings balance","formula":{"expression":"Future balance = starting balance x (1 + r)^n + monthly deposit x (((1 + r)^n - 1) / r)","label":"Savings interest formula","note":"This estimate assumes monthly compounding and steady monthly deposits."},"example":[{"label":"Starting balance","value":"$5,000"},{"label":"Monthly deposit","value":"$300"},{"label":"5 years at 4.5%","value":"$26,426"}],"sources":[{"href":"https://www.investor.gov/financial-tools-calculators/calculators/compound-interest-calculator","label":"Investor.gov","value":"Provides a compound interest calculator with initial investment, monthly contribution, time, interest rate, and compounding frequency inputs."},{"href":"https://www.fdic.gov/consumer-resource-center/deposit-accounts","label":"FDIC","value":"Explains savings accounts and deposit account basics."}]},{"slug":"apy-calculator","title":"APY Calculator","url":"https://toolkitshelf.com/tools/apy-calculator","category":"Money Calculators","formulaId":"toolkitshelf.formula.apy-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Starting balance","Interest rate","Compounding frequency","Years"],"resultLabel":"Annual percentage yield","formula":{"expression":"APY = (1 + interest rate / compounding periods) ^ compounding periods - 1","label":"APY formula","note":"This calculator converts a nominal annual interest rate into an effective annual percentage yield based on the compounding schedule you choose."},"example":[{"label":"Starting balance","value":"$10,000"},{"label":"Interest rate","value":"4.5%"},{"label":"Compounding","value":"Monthly"},{"label":"APY","value":"4.594%"}],"sources":[{"href":"https://www.consumerfinance.gov/rules-policy/regulations/1030/a/","label":"Consumer Financial Protection Bureau","value":"Regulation DD Appendix A explains annual percentage yield calculation for deposit accounts."},{"href":"https://www.fdic.gov/consumer-resource-center/deposit-accounts","label":"FDIC","value":"Explains deposit accounts, savings accounts, and insured bank account basics."}]},{"slug":"simple-interest-calculator","title":"Simple Interest Calculator","url":"https://toolkitshelf.com/tools/simple-interest-calculator","category":"Money Calculators","formulaId":"toolkitshelf.formula.simple-interest-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Principal","Annual rate","Years"],"resultLabel":"Simple interest","formula":{"expression":"Simple interest = principal x annual rate x time","label":"Simple interest formula","note":"The rate is entered as an annual percentage and time is entered in years."},"example":[{"label":"Principal","value":"$5,000"},{"label":"Annual rate","value":"6%"},{"label":"Time","value":"3 years"},{"label":"Simple interest","value":"$900"}],"sources":[{"href":"https://www.consumerfinance.gov/ask-cfpb/whats-the-difference-between-a-simple-interest-rate-and-precomputed-interest-on-an-auto-loan-en-841/","label":"Consumer Financial Protection Bureau","value":"Explains the difference between simple interest and precomputed interest on auto loans."},{"href":"https://www.investor.gov/financial-tools-calculators/calculators/compound-interest-calculator","label":"Investor.gov","value":"Explains how compounding differs from interest calculated only on the starting amount."}]},{"slug":"savings-withdrawal-calculator","title":"Savings Withdrawal Calculator","url":"https://toolkitshelf.com/tools/savings-withdrawal-calculator","category":"Money Calculators","formulaId":"toolkitshelf.formula.savings-withdrawal-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Starting savings","Monthly withdrawal","Monthly deposits","Annual return"],"resultLabel":"Savings duration","formula":{"expression":"Next balance = current balance x (1 + monthly return) + deposits - withdrawals; repeat monthly until balance reaches zero","label":"Savings withdrawal formula","note":"This is a planning estimate. Returns are assumed steady, but real savings and investments can fluctuate."},"example":[{"label":"Starting savings","value":"$50,000"},{"label":"Withdrawal","value":"$2,000/month"},{"label":"Annual return","value":"3%"},{"label":"Duration","value":"27 months"}],"sources":[{"href":"https://www.investor.gov/financial-tools-calculators/calculators/compound-interest-calculator","label":"Investor.gov","value":"Provides a compound-interest planning model that accepts monthly contributions or negative contributions for withdrawals."}]},{"slug":"compound-interest-calculator","title":"Compound Interest Calculator","url":"https://toolkitshelf.com/tools/compound-interest-calculator","category":"Money Calculators","formulaId":"toolkitshelf.formula.compound-interest-calculator","isCallableViaMcp":false,"lastReviewed":"2026-07-13","inputs":["Principal","Contribution","Rate","Years"],"resultLabel":"Future value","formula":{"expression":"Future value = principal x (1 + r)^n + monthly contribution x (((1 + r)^n - 1) / r), where r is monthly return and n is months","label":"Compound interest formula","note":"This calculator assumes monthly compounding, steady end-of-month contributions, and a constant annual return."},"example":[{"label":"Starting amount","value":"$10,000"},{"label":"Monthly contribution","value":"$250"},{"label":"10 years at 7%","value":"$63,368"},{"label":"Interest earned","value":"$23,368"}],"sources":[{"href":"https://www.investor.gov/financial-tools-calculators/calculators/compound-interest-calculator","label":"Investor.gov","value":"Provides a compound interest calculator and investor education from the U.S. Securities and Exchange Commission."}],"provenance":{"calculationClass":"estimate","intendedAudience":"People comparing long-term savings or investment scenarios from a starting amount, monthly contribution, assumed annual return, and time period.","maintainedBy":"Toolkit Shelf","materiallyReviewedAt":"2026-07-13","methodVersion":"toolkitshelf.compound-interest-monthly.v1","primarySource":{"href":"https://www.investor.gov/financial-tools-calculators/calculators/compound-interest-calculator","label":"Investor.gov Compound Interest Calculator","sourceDate":"Current calculator; accessed July 13, 2026"},"relianceBoundary":"This is a constant-return projection, not a forecast, guaranteed return, account statement, security recommendation, or substitute for investment and tax advice.","sourceCheckedAt":"2026-07-13","sourceFreshness":"Investor.gov's compound-interest inputs were checked on July 13, 2026. The Toolkit Shelf method uses a fixed monthly-compounding convention rather than live product rates.","validityConditions":"The result assumes a constant annual return compounded monthly and equal end-of-month contributions. It does not model volatility, taxes, fees, inflation, missed contributions, or changing returns."}},{"slug":"retirement-calculator","title":"Retirement Calculator","url":"https://toolkitshelf.com/tools/retirement-calculator","category":"Money Calculators","formulaId":"toolkitshelf.formula.retirement-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Current savings","Monthly contribution","Annual return","Years to invest","Target amount"],"resultLabel":"Projected retirement balance","formula":{"expression":"Future balance = current savings x (1 + r)^n + monthly contribution x (((1 + r)^n - 1) / r)","label":"Retirement projection formula","note":"This estimate assumes monthly compounding, steady monthly contributions, and no withdrawals before the target date."},"example":[{"label":"Current savings","value":"$75,000"},{"label":"Monthly contribution","value":"$700"},{"label":"25 years at 6%","value":"$819,969"},{"label":"Target gap","value":"$180,031 below $1M"}],"sources":[{"href":"https://www.investor.gov/financial-tools-calculators/calculators/compound-interest-calculator","label":"Investor.gov","value":"Provides a compound interest calculator for estimating savings growth with contributions and interest assumptions."},{"href":"https://www.ssa.gov/retirement/plan-for-retirement","label":"Social Security Administration","value":"Provides retirement planning resources and benefit-estimate guidance."}]},{"slug":"inflation-calculator","title":"Inflation Calculator","url":"https://toolkitshelf.com/tools/inflation-calculator","category":"Money Calculators","formulaId":"toolkitshelf.formula.inflation-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Current amount","Inflation rate","Years"],"resultLabel":"Future cost","formula":{"expression":"Future cost = current amount x (1 + inflation rate)^years","label":"Inflation formula","note":"This is a rate-based estimate, not a historical CPI lookup."},"example":[{"label":"Current amount","value":"$100"},{"label":"Inflation rate","value":"3%"},{"label":"Years","value":"10"},{"label":"Future cost","value":"$134.39"}],"sources":[{"href":"https://www.bls.gov/cpi/overview.htm","label":"U.S. Bureau of Labor Statistics","value":"Explains the Consumer Price Index and its use as a measure of price change and consumer inflation."}]},{"slug":"bmi-calculator","title":"BMI Calculator","url":"https://toolkitshelf.com/tools/bmi-calculator","category":"Health Calculators","formulaId":"toolkitshelf.formula.bmi-calculator","isCallableViaMcp":false,"lastReviewed":"2026-07-12","inputs":["Pounds or kilograms","Height","Unit system"],"resultLabel":"BMI","formula":{"expression":"BMI = kg / meters^2; US equivalent = pounds / inches^2 x 703","label":"BMI formula","note":"BMI is a screening measure and does not directly measure body fat or health. The calculator supports US and metric inputs."},"example":[{"label":"Weight","value":"180 lb / 81.6 kg"},{"label":"Height","value":"5 ft 10 in / 177.8 cm"},{"label":"BMI","value":"25.8"}],"sources":[{"href":"https://www.cdc.gov/bmi/adult-calculator/index.html","label":"Centers for Disease Control and Prevention","value":"Provides adult BMI categories and notes that BMI is a screening measure, not a substitute for medical advice."},{"href":"https://www.nist.gov/pml/owm/metric-si/unit-conversion/approximate-conversions-us-customary-measures-metric","label":"NIST","value":"Provides common U.S. customary to metric conversion references for length and mass."}],"provenance":{"calculationClass":"estimate","intendedAudience":"Adults age 20 and older who want a general BMI screening number from measured height and weight.","maintainedBy":"Toolkit Shelf","materiallyReviewedAt":"2026-07-12","methodVersion":"toolkitshelf.bmi-adult.v1","primarySource":{"href":"https://www.cdc.gov/bmi/adult-calculator/index.html","label":"CDC Adult BMI Calculator","sourceDate":"June 26, 2024"},"relianceBoundary":"BMI is a screening estimate, not a diagnosis, body-fat measurement, treatment recommendation, or substitute for professional medical advice.","sourceCheckedAt":"2026-07-12","sourceFreshness":"The CDC adult categories and screening limitations were checked on July 12, 2026. The internal method version changes only after a material formula or category change.","validityConditions":"Use adult inputs, measured height and weight, and the displayed unit conversion. Children, pregnancy, athletes, and individual medical context need different interpretation."}},{"slug":"ideal-weight-calculator","title":"Ideal Weight Calculator","url":"https://toolkitshelf.com/tools/ideal-weight-calculator","category":"Health Calculators","formulaId":"toolkitshelf.formula.ideal-weight-calculator","isCallableViaMcp":false,"lastReviewed":"2026-07-12","inputs":["Height","Current weight","Unit system"],"resultLabel":"BMI-based weight range","formula":{"expression":"Weight in kg = BMI x height in meters^2; US equivalent = BMI x height in inches^2 / 703","label":"BMI weight range formula","note":"This calculator supports pounds with feet/inches or kilograms with centimeters, using adult BMI 18.5 to 24.9 as a broad screening range."},"example":[{"label":"Height","value":"5 ft 10 in / 177.8 cm"},{"label":"BMI range","value":"18.5 - 24.9"},{"label":"Weight range","value":"129 - 174 lb / 58.5 - 78.7 kg"}],"sources":[{"href":"https://www.cdc.gov/bmi/adult-calculator/index.html","label":"Centers for Disease Control and Prevention","value":"Lists adult BMI categories and states that BMI is a screening measure, not intended to diagnose disease or illness."},{"href":"https://www.cdc.gov/obesity/downloads/BMIforPactitioners.pdf","label":"Centers for Disease Control and Prevention","value":"Explains that BMI should serve as an initial screening measure for adults."},{"href":"https://www.nist.gov/pml/owm/metric-si/si-units","label":"National Institute of Standards and Technology","value":"Publishes common inch, centimeter, pound, and kilogram conversion factors used for unit switching."}],"provenance":{"calculationClass":"estimate","intendedAudience":"Adults comparing a broad BMI-based weight range for a measured height, with current weight used only for context.","maintainedBy":"Toolkit Shelf","materiallyReviewedAt":"2026-07-12","methodVersion":"toolkitshelf.bmi-based-weight-range.v1","primarySource":{"href":"https://www.cdc.gov/bmi/adult-calculator/index.html","label":"CDC Adult BMI Calculator","sourceDate":"June 26, 2024"},"relianceBoundary":"The displayed 18.5 through 24.9 BMI range is not an individualized ideal weight, diagnosis, treatment goal, or substitute for medical context.","sourceCheckedAt":"2026-07-12","sourceFreshness":"The CDC adult BMI categories and screening limitations were checked on July 12, 2026. Toolkit Shelf derives the range by solving the BMI equation for weight.","validityConditions":"Use for adults age 20 and older with an accurate height. Children, pregnancy, athletes, edema, muscle mass, age-related change, and medical history need different interpretation."}},{"slug":"body-fat-calculator","title":"Body Fat Calculator","url":"https://toolkitshelf.com/tools/body-fat-calculator","category":"Health Calculators","formulaId":"toolkitshelf.formula.body-fat-calculator","isCallableViaMcp":false,"lastReviewed":"2026-07-12","inputs":["Sex","Weight","Height","Neck","Waist","Hip","Unit system"],"resultLabel":"Estimated body fat","formula":{"expression":"Men: 86.010 x log10(waist - neck) - 70.041 x log10(height) + 36.76; women: 163.205 x log10(waist + hip - neck) - 97.684 x log10(height) - 78.387","label":"U.S. Navy-style circumference formula","note":"The equation uses inches internally. Metric inputs are converted to inches before calculation, and tape estimates remain sensitive to measurement technique."},"example":[{"label":"Profile","value":"Female, 5 ft 6 in / 167.6 cm"},{"label":"Measurements","value":"13 in neck, 32 in waist, 40 in hips / 33, 81.3, 101.6 cm"},{"label":"Estimate","value":"About 33% body fat"}],"sources":[{"href":"https://www.mynavyhr.navy.mil/Portals/55/Support/Culture%20Resilience/Physical/Guide-4%20Body%20Composition%20Assessment.pdf","label":"U.S. Navy","value":"Publishes body composition assessment guidance with circumference-based body fat estimation tables."},{"href":"https://www.cdc.gov/bmi/adult-calculator/index.html","label":"Centers for Disease Control and Prevention","value":"Notes that BMI does not directly measure body fat, which is why body composition estimates need separate interpretation."},{"href":"https://www.nist.gov/pml/owm/metric-si/si-units","label":"National Institute of Standards and Technology","value":"Publishes common inch, centimeter, pound, and kilogram conversion factors used for unit switching."}],"provenance":{"calculationClass":"estimate","intendedAudience":"Adults using repeatable height, neck, waist, and where applicable hip measurements for a tape-based body-fat trend estimate.","maintainedBy":"Toolkit Shelf","materiallyReviewedAt":"2026-07-12","methodVersion":"toolkitshelf.body-fat-circumference.v1","primarySource":{"href":"https://api.army.mil/e2/c/downloads/566071.pdf","label":"U.S. Army Regulation 600-9 circumference equations","sourceDate":"June 28, 2013"},"relianceBoundary":"This is a circumference-based estimate, not a clinical body-composition measurement, diagnosis, service-eligibility decision, or substitute for professional assessment.","sourceCheckedAt":"2026-07-12","sourceFreshness":"The exact published circumference equations were checked on July 12, 2026. The calculator preserves those inch-based equations after visible unit conversion and does not assert current service policy.","validityConditions":"Use consistent anatomical landmarks, posture, breathing, and tape tension. Implausible or nonpositive circumference differences are invalid; the displayed estimate is bounded to 2% through 75% for interface safety."}},{"slug":"calorie-calculator","title":"Calorie Calculator","url":"https://toolkitshelf.com/tools/calorie-calculator","category":"Health Calculators","formulaId":"toolkitshelf.formula.calorie-calculator","isCallableViaMcp":false,"lastReviewed":"2026-07-12","inputs":["Sex","Age","Weight","Height","Activity level"],"resultLabel":"Maintenance calories","formula":{"expression":"Maintenance calories = Mifflin-St Jeor BMR x activity multiplier","label":"Calorie estimate formula","note":"This is a planning estimate. Actual needs vary by body composition, health, and activity."},"example":[{"label":"Profile","value":"35-year-old female"},{"label":"Height and weight","value":"5 ft 6 in, 165 lb"},{"label":"Activity","value":"Light activity"},{"label":"Maintenance","value":"2,017 calories/day"}],"sources":[{"href":"https://www.mayoclinic.org/healthy-lifestyle/weight-loss/in-depth/calorie-calculator/itt-20402304","label":"Mayo Clinic","value":"Provides a calorie calculator that estimates daily calorie needs from age, height, weight, sex, and activity level."},{"href":"https://pubmed.ncbi.nlm.nih.gov/2305711/","label":"PubMed","value":"Indexes the Mifflin-St Jeor resting energy expenditure paper used for the BMR portion of this estimate."}],"provenance":{"calculationClass":"estimate","intendedAudience":"Adults comparing general maintenance-calorie scenarios from age, height, weight, sex, and a broad activity assumption.","maintainedBy":"Toolkit Shelf","materiallyReviewedAt":"2026-07-12","methodVersion":"toolkitshelf.calorie-mifflin-activity.v1","primarySource":{"href":"https://pubmed.ncbi.nlm.nih.gov/2305711/","label":"Mifflin et al. resting-energy equation","sourceDate":"February 1990"},"relianceBoundary":"This is a planning estimate, not measured energy expenditure, medical nutrition therapy, or a personalized weight-change prescription.","sourceCheckedAt":"2026-07-12","sourceFreshness":"The published resting-energy equation is fixed; the selected activity multiplier remains a visible Toolkit Shelf planning assumption.","validityConditions":"The estimate assumes the entered measurements are accurate and the chosen activity level reasonably represents the usual routine. Individual needs can differ materially."}},{"slug":"bmr-calculator","title":"BMR Calculator","url":"https://toolkitshelf.com/tools/bmr-calculator","category":"Health Calculators","formulaId":"toolkitshelf.formula.bmr-calculator","isCallableViaMcp":false,"lastReviewed":"2026-07-12","inputs":["Sex","Age","Weight","Height"],"resultLabel":"Estimated BMR","formula":{"expression":"BMR = 10 x weight kg + 6.25 x height cm - 5 x age + 5 for men or -161 for women","label":"Mifflin-St Jeor equation","note":"BMR is an estimate of resting energy needs before activity is added."},"example":[{"label":"Profile","value":"35-year-old female"},{"label":"Height and weight","value":"5 ft 6 in, 165 lb"},{"label":"BMR","value":"About 1,455 calories/day"}],"sources":[{"href":"https://pubmed.ncbi.nlm.nih.gov/2305711/","label":"PubMed","value":"Indexes the 1990 Mifflin-St Jeor paper introducing a predictive equation for resting energy expenditure."},{"href":"https://www.ncbi.nlm.nih.gov/books/n/statpearls/article-29261/","label":"NCBI Bookshelf","value":"Explains that energy metabolism changes with rest, work, exercise, and other demands."}],"provenance":{"calculationClass":"estimate","intendedAudience":"Adults seeking a general resting-energy estimate from age, height, weight, and the equation's male or female coefficient.","maintainedBy":"Toolkit Shelf","materiallyReviewedAt":"2026-07-12","methodVersion":"toolkitshelf.bmr-mifflin.v1","primarySource":{"href":"https://pubmed.ncbi.nlm.nih.gov/2305711/","label":"Mifflin et al. resting-energy equation","sourceDate":"February 1990"},"relianceBoundary":"This is predicted resting energy expenditure, not indirect calorimetry, maintenance calories, medical nutrition therapy, or a personalized intake target.","sourceCheckedAt":"2026-07-12","sourceFreshness":"The published Mifflin equation and its adult study population were checked on July 12, 2026. The equation is fixed unless the internal method version changes.","validityConditions":"Use adult measurements and the coefficient that matches the equation input. Illness, pregnancy, medications, body-composition extremes, and individual metabolism can materially change actual needs."}},{"slug":"tdee-calculator","title":"TDEE Calculator","url":"https://toolkitshelf.com/tools/tdee-calculator","category":"Health Calculators","formulaId":"toolkitshelf.formula.tdee-calculator","isCallableViaMcp":false,"lastReviewed":"2026-07-12","inputs":["Sex","Age","Weight","Height","Activity level"],"resultLabel":"Estimated TDEE","formula":{"expression":"TDEE = Mifflin-St Jeor BMR x activity multiplier","label":"TDEE formula","note":"Activity multipliers are planning estimates, so real-world tracking is still important."},"example":[{"label":"Profile","value":"35-year-old female"},{"label":"Activity","value":"Light activity"},{"label":"Estimated TDEE","value":"About 2,000 calories/day"}],"sources":[{"href":"https://pubmed.ncbi.nlm.nih.gov/2305711/","label":"PubMed","value":"Indexes the Mifflin-St Jeor resting energy expenditure equation used for the BMR portion."},{"href":"https://www.niddk.nih.gov/bwp","label":"NIDDK","value":"Provides the NIH Body Weight Planner for estimating calorie needs and how physical activity affects weight goals."}],"provenance":{"calculationClass":"estimate","intendedAudience":"Adults comparing general maintenance-calorie scenarios from a Mifflin resting-energy estimate and a broad activity category.","maintainedBy":"Toolkit Shelf","materiallyReviewedAt":"2026-07-12","methodVersion":"toolkitshelf.tdee-mifflin-activity.v1","primarySource":{"href":"https://pubmed.ncbi.nlm.nih.gov/2305711/","label":"Mifflin et al. resting-energy equation","sourceDate":"February 1990"},"relianceBoundary":"This is not measured total energy expenditure, medical nutrition therapy, or a personalized loss or gain prescription; the plus-or-minus 300 calorie scenarios are planning examples.","sourceCheckedAt":"2026-07-12","sourceFreshness":"The Mifflin resting-energy equation was checked on July 12, 2026. Activity factors and 300-calorie scenarios are visible Toolkit Shelf heuristics, not part of the source paper.","validityConditions":"Use accurate adult measurements and an activity level that represents the usual week. Pregnancy, illness, medications, eating-disorder recovery, body-composition extremes, and changing activity require different guidance."}},{"slug":"macro-calculator","title":"Macro Calculator","url":"https://toolkitshelf.com/tools/macro-calculator","category":"Health Calculators","formulaId":"toolkitshelf.formula.macro-calculator","isCallableViaMcp":false,"lastReviewed":"2026-07-12","inputs":["Daily calories","Protein percent","Carb percent","Fat percent"],"resultLabel":"Macro grams","formula":{"expression":"Protein grams = protein calories / 4; carb grams = carb calories / 4; fat grams = fat calories / 9","label":"Macro gram formulas","note":"Protein and carbohydrates use about 4 calories per gram. 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Special fibers, sugar alcohols, and other exceptions are outside this calculator.","validityConditions":"The calorie input and percentages must reflect the user's chosen plan, and the percentages should total 100%. The general energy factors do not model every nutrient-label exception."}},{"slug":"protein-intake-calculator","title":"Protein Intake Calculator","url":"https://toolkitshelf.com/tools/protein-intake-calculator","category":"Health Calculators","formulaId":"toolkitshelf.formula.protein-intake-calculator","isCallableViaMcp":false,"lastReviewed":"2026-07-12","inputs":["Weight","Protein target","Meals per day"],"resultLabel":"Daily protein target","formula":{"expression":"Protein grams per day = body weight in kg x grams per kg target","label":"Protein intake formula","note":"The adult RDA baseline is 0.8 g/kg for healthy adults; active targets are planning estimates."},"example":[{"label":"Weight","value":"170 lb"},{"label":"Target","value":"0.8 g/kg"},{"label":"Protein","value":"62 g/day"}],"sources":[{"href":"https://www.ncbi.nlm.nih.gov/sites/books/n/statpearls/article-157662/","label":"NCBI Bookshelf","value":"States that the current recommended daily allowance of protein for healthy adults is 0.8 g/kg."},{"href":"https://pmc.ncbi.nlm.nih.gov/articles/PMC7850043/","label":"PMC","value":"Reviews U.S. protein recommendations and notes the adult RDA of 0.8 g/kg body weight."}],"provenance":{"calculationClass":"estimate","intendedAudience":"Healthy adults comparing a general 0.8 g/kg baseline with optional 1.2 or 1.6 g/kg active-planning scenarios.","maintainedBy":"Toolkit Shelf","materiallyReviewedAt":"2026-07-12","methodVersion":"toolkitshelf.protein-bodyweight-target.v1","primarySource":{"href":"https://pubmed.ncbi.nlm.nih.gov/26891166/","label":"ACSM joint position on nutrition and athletic performance","sourceDate":"March 2016"},"relianceBoundary":"The selected grams-per-kilogram value is a planning scenario, not a personalized requirement, supplement recommendation, treatment plan, or assessment of protein quality.","sourceCheckedAt":"2026-07-12","sourceFreshness":"The adult 0.8 g/kg reference baseline and sports-nutrition range containing the 1.2 and 1.6 presets were checked on July 12, 2026.","validityConditions":"Use measured adult body weight and choose a scenario that fits the actual activity context. Pregnancy, kidney disease, illness, energy restriction, elite training, and other clinical needs require qualified guidance."}},{"slug":"water-intake-calculator","title":"Water Intake Calculator","url":"https://toolkitshelf.com/tools/water-intake-calculator","category":"Health Calculators","formulaId":"toolkitshelf.formula.water-intake-calculator","isCallableViaMcp":false,"lastReviewed":"2026-07-12","inputs":["Profile","Exercise minutes","Hot weather days"],"resultLabel":"Estimated total water","formula":{"expression":"Estimated total water = reference adequate intake + exercise add-on + hot-weather add-on","label":"Water intake estimate","note":"Reference adequate intakes include water from both food and beverages."},"example":[{"label":"Profile","value":"Adult female"},{"label":"Exercise","value":"30 minutes/day"},{"label":"Baseline","value":"2.7 L/day"},{"label":"Estimated total","value":"3.1 L/day"}],"sources":[{"href":"https://www.nationalacademies.org/read/10925/chapter/2","label":"National Academies","value":"Lists total water adequate intakes of 3.7 L/day for young men and 2.7 L/day for young women."},{"href":"https://medlineplus.gov/ency/article/002471.htm","label":"MedlinePlus","value":"Summarizes adult dietary reference intakes for water as roughly 2.7 to 3.7 liters per day."}],"provenance":{"calculationClass":"estimate","intendedAudience":"Generally healthy adults comparing total-water adequate-intake reference values with rough exercise and hot-weather planning add-ons.","maintainedBy":"Toolkit Shelf","materiallyReviewedAt":"2026-07-12","methodVersion":"toolkitshelf.water-ai-addons.v1","primarySource":{"href":"https://www.nationalacademies.org/read/10925/chapter/2","label":"National Academies total-water dietary reference intake","sourceDate":"2005"},"relianceBoundary":"This is not a hydration prescription, fluid-balance assessment, heat-safety plan, or substitute for thirst, symptoms, medical restrictions, and qualified guidance.","sourceCheckedAt":"2026-07-12","sourceFreshness":"The National Academies total-water baselines and their variability limits were checked on July 12, 2026. Exercise, heat, and 80% beverage adjustments are Toolkit Shelf planning heuristics.","validityConditions":"The baseline represents total water from food and beverages for generally healthy people. Climate, exertion, pregnancy, lactation, medications, kidney or heart conditions, and acute illness can change needs substantially."}},{"slug":"due-date-calculator","title":"Due Date Calculator","url":"https://toolkitshelf.com/tools/due-date-calculator","category":"Health Calculators","formulaId":"toolkitshelf.formula.due-date-calculator","isCallableViaMcp":false,"lastReviewed":"2026-07-12","inputs":["First day of last period","Average cycle length"],"resultLabel":"Estimated due date","formula":{"expression":"Due date = first day of last period + 280 days + cycle adjustment","label":"Due date estimate","note":"This is a common estimate and does not replace ultrasound dating or medical care."},"example":[{"label":"Last period","value":"May 1, 2026"},{"label":"Cycle length","value":"28 days"},{"label":"Estimated due date","value":"Feb 5, 2027"}],"sources":[{"href":"https://www.acog.org/womens-health/faqs/when-pregnancy-goes-past-your-due-date","label":"ACOG","value":"States that estimated due date is calculated from the first day of the last menstrual period and average pregnancy length is 280 days or 40 weeks."},{"href":"https://www.acog.org/clinical/clinical-guidance/committee-opinion/articles/2017/05/methods-for-estimating-the-due-date","label":"ACOG","value":"Provides clinical guidance on methods for estimating due date and recording gestational age."}],"provenance":{"calculationClass":"estimate","intendedAudience":"People making a rough pregnancy due-date estimate from a known last menstrual period and average cycle length.","maintainedBy":"Toolkit Shelf","materiallyReviewedAt":"2026-07-12","methodVersion":"toolkitshelf.pregnancy-due-date-lmp.v1","primarySource":{"href":"https://www.acog.org/clinical/clinical-guidance/committee-opinion/articles/2017/05/methods-for-estimating-the-due-date","label":"ACOG Committee Opinion No. 700","sourceDate":"May 2017; reaffirmed 2025"},"relianceBoundary":"This is an LMP-based planning estimate, not clinical dating, prenatal care, an ultrasound interpretation, or a replacement for a clinician-assigned due date.","sourceCheckedAt":"2026-07-12","sourceFreshness":"ACOG Committee Opinion No. 700 and its reaffirmed status were checked on July 12, 2026.","validityConditions":"The estimate assumes the last menstrual period is known and uses the entered cycle adjustment. Assisted reproduction, irregular cycles, and ultrasound findings require clinical dating."}},{"slug":"pregnancy-week-calculator","title":"Pregnancy Week Calculator","url":"https://toolkitshelf.com/tools/pregnancy-week-calculator","category":"Health Calculators","formulaId":"toolkitshelf.formula.pregnancy-week-calculator","isCallableViaMcp":false,"lastReviewed":"2026-07-12","inputs":["Last menstrual period","Cycle length","As-of date"],"resultLabel":"Estimated gestational age","formula":{"expression":"Gestational age = days since first day of last menstrual period / 7","label":"Pregnancy week formula","note":"A 40-week estimate is commonly counted from the first day of the last menstrual period."},"example":[{"label":"Last period","value":"May 1, 2026"},{"label":"As of","value":"May 26, 2026"},{"label":"Pregnancy week","value":"3w 4d"}],"sources":[{"href":"https://www.acog.org/womens-health/faqs/when-pregnancy-goes-past-your-due-date","label":"ACOG","value":"States that estimated due date is calculated from the first day of the last menstrual period and average pregnancy length is 280 days or 40 weeks."},{"href":"https://www.acog.org/clinical/clinical-guidance/committee-opinion/articles/2017/05/methods-for-estimating-the-due-date","label":"ACOG","value":"Provides clinical guidance on methods for estimating the due date and documenting gestational age."}],"provenance":{"calculationClass":"estimate","intendedAudience":"People making a rough gestational-age estimate from a known last menstrual period and chosen as-of date.","maintainedBy":"Toolkit Shelf","materiallyReviewedAt":"2026-07-12","methodVersion":"toolkitshelf.pregnancy-week-lmp.v1","primarySource":{"href":"https://www.acog.org/clinical/clinical-guidance/committee-opinion/articles/2017/05/methods-for-estimating-the-due-date","label":"ACOG Committee Opinion No. 700","sourceDate":"May 2017; reaffirmed 2025"},"relianceBoundary":"This is an LMP-based planning estimate, not clinical gestational dating, prenatal care, or a replacement for ultrasound and clinician review.","sourceCheckedAt":"2026-07-12","sourceFreshness":"ACOG Committee Opinion No. 700 and its reaffirmed status were checked on July 12, 2026.","validityConditions":"The estimate assumes the last menstrual period and as-of date are correct. Assisted reproduction, irregular cycles, and ultrasound findings require clinical interpretation."}},{"slug":"conception-date-calculator","title":"Conception Date Calculator","url":"https://toolkitshelf.com/tools/conception-date-calculator","category":"Health Calculators","formulaId":"toolkitshelf.formula.conception-date-calculator","isCallableViaMcp":false,"lastReviewed":"2026-07-12","inputs":["Estimated due date"],"resultLabel":"Estimated conception date","formula":{"expression":"Estimated conception date = estimated due date - 266 days","label":"Conception date estimate","note":"This is an estimate. 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The plus-or-minus three-day window is a visible Toolkit Shelf planning convention.","validityConditions":"The entered due date must already be a reliable obstetric estimate. 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Review each version for accuracy, voice, proof, platform length, and the real promise behind the profile."},"example":[{"label":"Name","value":"Toolkit Shelf"},{"label":"Role","value":"a free calculator library that shows its work"},{"label":"Audience","value":"people checking everyday numbers"},{"label":"Output","value":"8 bio options with usage notes"}],"sources":[]},{"slug":"cta-generator","title":"CTA Generator","url":"https://toolkitshelf.com/tools/cta-generator","category":"Text and Writing Tools","formulaId":"toolkitshelf.formula.cta-generator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Offer or page promise","Audience","Desired action","Goal or outcome","Context","Tone","Urgency"],"resultLabel":"CTA ideas","formula":{"expression":"CTA ideas = offer + audience + desired action + goal + publishing context + tone + urgency","label":"CTA generation method","note":"The generator creates structured CTA drafts. Review each CTA for accuracy, pressure level, link destination, and whether the promised next step is real."},"example":[{"label":"Offer","value":"free calculators that show the formula"},{"label":"Audience","value":"people checking everyday numbers"},{"label":"Action","value":"try a calculator"},{"label":"Output","value":"8 CTA options with usage notes"}],"sources":[]},{"slug":"domain-name-generator","title":"Domain Name Generator","url":"https://toolkitshelf.com/tools/domain-name-generator","category":"Text and Writing Tools","formulaId":"toolkitshelf.formula.domain-name-generator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Core word or brand","Niche or descriptor","Audience or benefit","Style","TLD","Length"],"resultLabel":"Domain name ideas","formula":{"expression":"Domain ideas = cleaned core word + niche word + benefit word + style prefixes and suffixes + selected TLD","label":"Domain generation method","note":"The generator creates structured name candidates. It does not check live availability, trademarks, social handles, or brand conflicts."},"example":[{"label":"Core word","value":"toolkit"},{"label":"Descriptor","value":"calculator"},{"label":"TLD","value":".com"},{"label":"Output","value":"8 domain ideas with usage notes"}],"sources":[]},{"slug":"utm-link-builder","title":"UTM Link Builder","url":"https://toolkitshelf.com/tools/utm-link-builder","category":"Utility Tools","formulaId":"toolkitshelf.formula.utm-link-builder","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Destination URL","Campaign source","Campaign medium","Campaign name","Campaign ID","Source platform","Term","Content","Creative format","Marketing tactic"],"resultLabel":"Campaign tracking URL","formula":{"expression":"UTM URL = destination URL + encoded utm_source + utm_medium + utm_campaign + optional UTM fields","label":"UTM link method","note":"The output uses URL query parameters. Analytics reporting quality depends on consistent naming, valid destination URLs, and the analytics setup on the destination site."},"example":[{"label":"Email","value":"utm_source=newsletter, utm_medium=email"},{"label":"Paid social","value":"utm_source=instagram, utm_medium=paid_social"},{"label":"QR campaign","value":"utm_content=poster-a before creating the QR code"}],"sources":[{"href":"https://support.google.com/analytics/answer/10917952?hl=en","label":"Google Analytics Help","value":"Documents UTM parameters, URL builder guidance, and the recommendation to use source, medium, and campaign fields."},{"href":"https://developer.mozilla.org/en-US/docs/Web/API/URLSearchParams","label":"MDN Web Docs","value":"Documents URLSearchParams behavior for encoding and serializing query parameters in the browser."}]},{"slug":"json-formatter-validator","title":"JSON Formatter / Validator","url":"https://toolkitshelf.com/tools/json-formatter-validator","category":"Utility Tools","formulaId":"toolkitshelf.formula.json-formatter-validator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["JSON input","Format mode","Indentation","Sort object keys"],"resultLabel":"Formatted JSON","formula":{"expression":"Output = JSON.parse(input), then JSON.stringify(parsed value, optional sorted keys, selected indentation)","label":"JSON formatting method","note":"The formatter accepts strict JSON, not JavaScript object literals with comments, trailing commas, or unquoted keys."},"example":[{"label":"Input","value":"{\"name\":\"Toolkit\",\"public\":true}"},{"label":"Mode","value":"Format JSON with 2-space indentation"},{"label":"Output","value":"Readable JSON plus object, key, and depth counts"}],"sources":[{"href":"https://ecma-international.org/publications-and-standards/standards/ecma-404/","label":"ECMA-404","value":"Defines JSON as a lightweight data interchange syntax with objects, arrays, strings, numbers, booleans, and null."},{"href":"https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON","label":"MDN Web Docs","value":"Documents JSON.parse and JSON.stringify behavior in JavaScript."}]},{"slug":"jwt-decoder-claims-inspector","title":"JWT Decoder and Claims Inspector","url":"https://toolkitshelf.com/tools/jwt-decoder-claims-inspector","category":"Utility Tools","formulaId":"toolkitshelf.formula.jwt-decoder-claims-inspector","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Compact token","Header","Payload","Signature segment","Claims","Time claims"],"resultLabel":"Decoded JWT header and claims","formula":{"expression":"Decoded JWT = split compact token into header.payload.signature + Base64URL-decode header and payload + JSON.parse claims + compare NumericDate claims with current time","label":"Compact token decoding method","note":"This decoder does not verify signatures or fetch signing keys. Use it to inspect token contents, not to prove a token is trusted."},"example":[{"label":"Header","value":"{\"alg\":\"HS256\",\"typ\":\"JWT\"}"},{"label":"Payload claim","value":"sub=user_123, aud=toolkitshelf, exp=4102444800"},{"label":"Output","value":"Decoded JSON, claim table, UTC time checks, and verification warning"}],"sources":[{"href":"https://www.rfc-editor.org/rfc/rfc7519.txt","label":"RFC 7519","value":"Defines JSON Web Token structure, registered claims, NumericDate values, and compact serialization."},{"href":"https://www.rfc-editor.org/rfc/rfc7515.txt","label":"RFC 7515","value":"Defines JSON Web Signature compact serialization and JOSE header behavior used by signed JWTs."}]},{"slug":"text-json-diff-checker","title":"Text and JSON Diff Checker","url":"https://toolkitshelf.com/tools/text-json-diff-checker","category":"Utility Tools","formulaId":"toolkitshelf.formula.text-json-diff-checker","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Left input","Right input","Compare mode","Text options","JSON normalization"],"resultLabel":"Line diff preview and similarity","formula":{"expression":"Diff rows = optional JSON.parse + sorted-key JSON.stringify + line split + longest common subsequence alignment + added, removed, replacement-block, and similarity counts","label":"Text and JSON diff method","note":"JSON mode sorts object keys before comparing, so key-order-only differences are treated as unchanged."},"example":[{"label":"Left JSON","value":"{\"active\":true,\"count\":291}"},{"label":"Right JSON","value":"{\"count\":292,\"active\":false}"},{"label":"Output","value":"Sorted-key JSON diff with added, removed, changed-block, and similarity counts"}],"sources":[{"href":"https://ecma-international.org/publications-and-standards/standards/ecma-404/","label":"ECMA-404","value":"Defines JSON syntax and value types used when JSON mode parses and normalizes payloads."},{"href":"https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON","label":"MDN Web Docs","value":"Documents JSON.parse and JSON.stringify behavior in JavaScript."}]},{"slug":"cron-expression-explainer","title":"Cron Expression Explainer and Next Run Preview","url":"https://toolkitshelf.com/tools/cron-expression-explainer","category":"Utility Tools","formulaId":"toolkitshelf.formula.cron-expression-explainer","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Cron expression","Start after","Preview time","Minute field","Hour field","Day fields"],"resultLabel":"Cron field breakdown and next runs","formula":{"expression":"Next runs = parse five cron fields + expand wildcards, lists, ranges, steps, month names, and weekday names + match future minutes against minute, hour, month, and day rules","label":"Cron preview method","note":"This explainer supports standard five-field cron syntax. It does not model seconds, years, Quartz modifiers, Jenkins H, L, W, #, or ? tokens."},"example":[{"label":"Weekday schedule","value":"*/15 9-17 * * MON-FRI"},{"label":"Meaning","value":"Every 15 minutes during hours 09 through 17 on Monday through Friday"},{"label":"Output","value":"Field meanings, upcoming run times, timezone basis, and dialect warnings"}],"sources":[{"href":"https://man7.org/linux/man-pages/man5/crontab.5.html","label":"man7.org","value":"Documents crontab field order, ranges, lists, steps, names, and day-of-month/day-of-week matching behavior."},{"href":"https://pubs.opengroup.org/onlinepubs/9699919799/utilities/crontab.html","label":"The Open Group","value":"Documents POSIX crontab utility behavior and the five time-and-date fields used by standard cron entries."}]},{"slug":"hash-generator-checksum-tool","title":"Hash Generator and Checksum Tool","url":"https://toolkitshelf.com/tools/hash-generator-checksum-tool","category":"Utility Tools","formulaId":"toolkitshelf.formula.hash-generator-checksum-tool","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Text to hash","File to checksum","SHA-256","SHA-384","SHA-512","UTF-8 or raw file bytes"],"resultLabel":"Hex, Base64, and Base64URL hashes","formula":{"expression":"Digest = Web Crypto SHA-256, SHA-384, or SHA-512 over UTF-8 encoded text or raw file bytes, then encode digest bytes as hex, Base64, and Base64URL","label":"Hash generation method","note":"Hashes verify exact input equality. They are deterministic checksums, not encryption, and whitespace, line-ending, or file-byte differences change the digest."},"example":[{"label":"Input","value":"Toolkit Shelf"},{"label":"SHA-256 hex","value":"b0bd1f046b44f4c1cc6950b62d1c77fbbb8c27b09b42c521ce6c7a313e3d44b9"},{"label":"Output formats","value":"Hex, Base64, and Base64URL digest strings"}],"sources":[{"href":"https://www.w3.org/TR/WebCryptoAPI/","label":"W3C Web Crypto API","value":"Defines the browser SubtleCrypto digest operation used for SHA-2 hash generation."},{"href":"https://developer.mozilla.org/en-US/docs/Web/API/SubtleCrypto/digest","label":"MDN Web Docs","value":"Documents SubtleCrypto.digest support for SHA-256, SHA-384, and SHA-512 in browsers."}]},{"slug":"regex-tester-explainer","title":"Regex Tester and Explainer","url":"https://toolkitshelf.com/tools/regex-tester-explainer","category":"Utility Tools","formulaId":"toolkitshelf.formula.regex-tester-explainer","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Regex pattern","JavaScript flags","Sample text","Matches","Capture groups","Pattern explanation"],"resultLabel":"Regex matches and pattern notes","formula":{"expression":"Match report = JavaScript RegExp(pattern, flags) + bounded global scan over sample text + capture group extraction + pattern token notes","label":"Regex testing method","note":"The tester uses the browser JavaScript regular expression engine. Regex flavor, Unicode handling, lookbehind support, and performance can differ from other languages."},"example":[{"label":"Email pattern","value":"\\b([\\w.%+-]+)@([\\w.-]+\\.[a-z]{2,})\\b"},{"label":"Flags","value":"g and i for global, case-insensitive matching"},{"label":"Output","value":"Match index, matched text, and captured username/domain groups"}],"sources":[{"href":"https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_expressions","label":"MDN Web Docs","value":"Documents JavaScript regular expressions, syntax, assertions, groups, quantifiers, and flags."},{"href":"https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp","label":"MDN Web Docs","value":"Documents the RegExp object, flags, match behavior, and browser compatibility."}]},{"slug":"color-converter","title":"Color Converter HEX / RGB / HSL","url":"https://toolkitshelf.com/tools/color-converter","category":"Utility Tools","formulaId":"toolkitshelf.formula.color-converter","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["HEX color","RGB color","HSL color"],"resultLabel":"Converted color values","formula":{"expression":"HEX, RGB, and HSL values are normalized to sRGB channels, then converted with standard hue, saturation, lightness, and luminance formulas","label":"sRGB color conversion method","note":"The contrast helper compares black and white text only. Full accessibility checks still depend on font size, weight, state, and surrounding UI."},"example":[{"label":"HEX","value":"#336699"},{"label":"RGB","value":"rgb(51, 102, 153)"},{"label":"HSL","value":"hsl(210 50% 40%)"}],"sources":[{"href":"https://www.w3.org/TR/css-color-4/","label":"CSS Color Module","value":"Defines CSS color syntaxes and color functions used by browsers."},{"href":"https://www.w3.org/WAI/WCAG22/Understanding/contrast-minimum.html","label":"WCAG contrast","value":"Defines relative luminance and contrast ratio concepts used for text readability checks."}]},{"slug":"csv-tsv-formatter-cleaner","title":"CSV / TSV Formatter + Cleaner","url":"https://toolkitshelf.com/tools/csv-tsv-formatter-cleaner","category":"Utility Tools","formulaId":"toolkitshelf.formula.csv-tsv-formatter-cleaner","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["CSV or TSV input","Input delimiter","Output format","Trim cells","Remove empty rows"],"resultLabel":"Cleaned CSV or TSV text","formula":{"expression":"Output = parse quoted delimited rows, optionally trim cells and remove empty rows, pad ragged rows, then serialize as CSV or TSV","label":"Delimited text cleanup method","note":"Quoted CSV cells and doubled quotes are supported. Very large files are better handled in a spreadsheet or scripted data pipeline."},"example":[{"label":"Input","value":"Name, Count\\n Alice , 12"},{"label":"Cleaned CSV","value":"Name,Count\\nAlice,12"},{"label":"TSV output","value":"Name<TAB>Count"}],"sources":[{"href":"https://www.rfc-editor.org/rfc/rfc4180.txt","label":"RFC 4180","value":"Documents the common CSV format conventions for records, fields, quotes, and doubled quotes."},{"href":"https://www.w3.org/TR/tabular-data-primer/","label":"W3C CSV on the Web","value":"Provides web-oriented guidance for tabular data, CSV metadata, and CSV processing expectations."}]},{"slug":"markdown-table-generator","title":"Markdown Table Generator","url":"https://toolkitshelf.com/tools/markdown-table-generator","category":"Utility Tools","formulaId":"toolkitshelf.formula.markdown-table-generator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["CSV or TSV input","Input delimiter","Column alignment","Trim cells"],"resultLabel":"Markdown pipe table","formula":{"expression":"Output = parse delimited rows, normalize table width, escape Markdown pipe characters, then serialize header, alignment row, and body rows","label":"Markdown pipe table method","note":"The generator follows GitHub-flavored Markdown table conventions and treats the first input row as the header row."},"example":[{"label":"Input","value":"Name, Score\\nAlice, 12"},{"label":"Markdown","value":"| Name | Score |"},{"label":"Alignment row","value":"| :--- | :--- |"}],"sources":[{"href":"https://github.github.com/gfm/#tables-extension-","label":"GitHub Flavored Markdown","value":"Defines the pipe table extension, delimiter rows, and alignment markers commonly used in READMEs and issues."},{"href":"https://www.markdownguide.org/extended-syntax/#tables","label":"Markdown Guide","value":"Documents common table syntax, separator rows, and column alignment examples for extended Markdown."}]},{"slug":"uuid-generator","title":"UUID Generator","url":"https://toolkitshelf.com/tools/uuid-generator","category":"Utility Tools","formulaId":"toolkitshelf.formula.uuid-generator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["How many","Casing","Wrapper","Hyphen option"],"resultLabel":"Random UUID v4 values","formula":{"expression":"UUID v4 = 16 random bytes with version bits set to 0100 and RFC variant bits set to 10","label":"UUID v4 generation method","note":"UUIDs are identifiers, not secrets. Do not use generated UUIDs as passwords, API keys, or authorization tokens."},"example":[{"label":"Version","value":"UUID v4"},{"label":"Shape","value":"xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx"},{"label":"URN option","value":"urn:uuid:..."}],"sources":[{"href":"https://www.rfc-editor.org/rfc/rfc9562.txt","label":"RFC 9562","value":"Defines UUID formats, variants, and the UUID version 4 random generation layout."},{"href":"https://developer.mozilla.org/en-US/docs/Web/API/Crypto/randomUUID","label":"MDN Web Docs","value":"Documents browser support for crypto.randomUUID and secure random UUID generation."}]},{"slug":"base64-encoder-decoder","title":"Base64 Encoder / Decoder","url":"https://toolkitshelf.com/tools/base64-encoder-decoder","category":"Utility Tools","formulaId":"toolkitshelf.formula.base64-encoder-decoder","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Text input","Base64 input","Mode","Output variant","Padding"],"resultLabel":"Encoded or decoded text","formula":{"expression":"Base64 output = UTF-8 bytes grouped into 6-bit values and mapped to the Base64 alphabet","label":"Base64 encoding method","note":"Base64 is encoding, not encryption. URL-safe Base64 replaces + and / with - and _ and may omit padding."},"example":[{"label":"Text","value":"Toolkit Shelf"},{"label":"Base64","value":"VG9vbGtpdCBTaGVsZg=="},{"label":"URL-safe option","value":"Uses - and _ instead of + and /"}],"sources":[{"href":"https://www.rfc-editor.org/rfc/rfc4648.txt","label":"RFC 4648","value":"Defines Base64 and Base64URL alphabets, padding behavior, and common base encoding rules."},{"href":"https://developer.mozilla.org/en-US/docs/Glossary/Base64","label":"MDN Web Docs","value":"Documents Base64 encoding and decoding concepts for web APIs."}]},{"slug":"html-entity-encoder-decoder","title":"HTML Entity Encoder / Decoder","url":"https://toolkitshelf.com/tools/html-entity-encoder-decoder","category":"Utility Tools","formulaId":"toolkitshelf.formula.html-entity-encoder-decoder","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Text or HTML snippet","Entity input","Mode","Quote handling","Non-ASCII option"],"resultLabel":"Encoded or decoded HTML entity text","formula":{"expression":"Output = replace reserved HTML text characters with named or numeric character references, or reverse valid references to Unicode text","label":"HTML entity escaping method","note":"HTML entity encoding helps text display safely as text, but it is not a full HTML sanitizer."},"example":[{"label":"Input","value":"Tom & Jerry <span>"},{"label":"Encoded","value":"Tom &amp; Jerry &lt;span&gt;"},{"label":"Numeric example","value":"&#169; decodes to the copyright symbol"}],"sources":[{"href":"https://html.spec.whatwg.org/multipage/named-characters.html","label":"WHATWG HTML","value":"Defines character references and the parsing model used by browsers."},{"href":"https://developer.mozilla.org/en-US/docs/Glossary/Character_reference","label":"MDN Web Docs","value":"Documents how reserved characters and character references behave in HTML text."}]},{"slug":"url-encoder-decoder","title":"URL Encoder / Decoder","url":"https://toolkitshelf.com/tools/url-encoder-decoder","category":"Utility Tools","formulaId":"toolkitshelf.formula.url-encoder-decoder","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Mode","Input text","URL component","Full URL","Form query value","Encoded text"],"resultLabel":"Encoded or decoded URL text","formula":{"expression":"Output = input transformed with encodeURIComponent, decodeURIComponent, encodeURI, decodeURI, or form-style plus handling","label":"URL encoding method","note":"Use component encoding for individual query values and path segments. Use full URL encoding only when the URL syntax itself should be preserved."},"example":[{"label":"Component encode","value":"spring launch -> spring%20launch"},{"label":"Reserved characters","value":"a=b&c=d -> a%3Db%26c%3Dd"},{"label":"Form query","value":"hello world -> hello+world"}],"sources":[{"href":"https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/encodeURIComponent","label":"MDN Web Docs","value":"Documents encodeURIComponent and when component encoding is safer than encoding an entire URL."},{"href":"https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/decodeURIComponent","label":"MDN Web Docs","value":"Documents decodeURIComponent behavior and malformed escape handling."},{"href":"https://developer.mozilla.org/en-US/docs/Web/API/URLSearchParams","label":"MDN Web Docs","value":"Documents URLSearchParams and browser support for query-string work."}]},{"slug":"url-parser-query-string-inspector","title":"URL Parser / Query String Inspector","url":"https://toolkitshelf.com/tools/url-parser-query-string-inspector","category":"Utility Tools","formulaId":"toolkitshelf.formula.url-parser-query-string-inspector","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["URL or domain","Query string","URL parameters","UTM parameters","Hash fragment","Path"],"resultLabel":"Parsed URL parts and query parameters","formula":{"expression":"Parsed URL = browser URL parts + decoded query rows + duplicate, empty, UTM, credential, hash, and length checks","label":"URL inspection method","note":"The inspector uses the browser URL parser. It can assume https:// for bare domains, but destination behavior still depends on the real server and redirect chain."},"example":[{"label":"Campaign URL","value":"utm_source, utm_medium, utm_campaign, and creative fields"},{"label":"Duplicate key","value":"table=12&table=patio is flagged for review"},{"label":"Fragment","value":"#menu is shown separately because fragments are not sent to servers"}],"sources":[{"href":"https://developer.mozilla.org/en-US/docs/Web/API/URL","label":"MDN Web Docs","value":"Documents the URL API used by browsers to parse and normalize URL components."},{"href":"https://developer.mozilla.org/en-US/docs/Web/API/URLSearchParams","label":"MDN Web Docs","value":"Documents URLSearchParams and browser support for working with URL query parameters."}]},{"slug":"query-string-cleaner","title":"Query String Cleaner","url":"https://toolkitshelf.com/tools/query-string-cleaner","category":"Utility Tools","formulaId":"toolkitshelf.formula.query-string-cleaner","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Messy URL","Tracking parameter removal","UTM preservation","Duplicate key rule","Empty value removal","Sort order","Hash fragment"],"resultLabel":"Cleaned URL and query string","formula":{"expression":"Clean URL = parsed URL - selected tracking params - empty values - duplicate keys + optional sorted query + optional hash removal","label":"Query cleanup method","note":"Cleaning a query string can change attribution, personalization, filters, or redirect behavior. Test the cleaned link before using it publicly."},"example":[{"label":"Ad click IDs","value":"fbclid, gclid, msclkid, ttclid, and similar IDs"},{"label":"UTM choice","value":"Keep campaign labels for reporting or strip them for sharing"},{"label":"Duplicate key","value":"table=12&table=patio can keep first, keep last, or keep both"}],"sources":[{"href":"https://developer.mozilla.org/en-US/docs/Web/API/URLSearchParams","label":"MDN Web Docs","value":"Documents URLSearchParams behavior for reading, editing, and serializing query parameters."},{"href":"https://developer.mozilla.org/en-US/docs/Web/API/URL","label":"MDN Web Docs","value":"Documents the URL API used by browsers to parse and rebuild URLs."}]},{"slug":"redirect-chain-checker","title":"Redirect Chain Checker","url":"https://toolkitshelf.com/tools/redirect-chain-checker","category":"Utility Tools","formulaId":"toolkitshelf.formula.redirect-chain-checker","isCallableViaMcp":false,"lastReviewed":"2026-07-12","inputs":["URL to check","HTTP status","Redirect chain","Final URL","Content type","Response time"],"resultLabel":"Redirect chain and final URL status","formula":{"expression":"Redirect report = guarded HEAD request + manual Location following + final status + hop timing + unsafe-destination blocks","label":"Redirect check method","note":"The checker blocks localhost, private IPs, reserved IPs, credentialed URLs, and non-http destinations before each request and after each redirect."},"example":[{"label":"QR destination","value":"Check whether a printed link resolves before generating the QR code"},{"label":"Campaign link","value":"Confirm whether UTM or tracking redirects end on the intended page"},{"label":"Support ticket","value":"Paste a failing URL and capture status, hops, and final target"}],"sources":[{"href":"https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API","label":"MDN Web Docs","value":"Documents the Fetch API used for request metadata and manual redirect handling."},{"href":"https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Status","label":"MDN Web Docs","value":"Documents HTTP response status codes used to interpret redirect, success, and error responses."},{"href":"https://developer.mozilla.org/en-US/docs/Web/API/URL","label":"MDN Web Docs","value":"Documents the URL API used to parse input URLs and resolve relative redirect locations."}],"provenance":{"calculationClass":"external-data","intendedAudience":"Site owners, developers, editors, and launch reviewers checking one public URL at a time.","maintainedBy":"Toolkit Shelf","materiallyReviewedAt":"2026-07-12","primarySource":{"label":"User-provided public URL","sourceDate":"At each run"},"sourceCheckedAt":"2026-07-12","sourceFreshness":"Each result is a point-in-time server request. Rerun the checker after the page, server, cache, or redirect behavior changes.","methodVersion":"toolkitshelf.redirect-chain-guarded-fetch.v1","relianceBoundary":"The report shows one server-side redirect path, not every browser, geography, user agent, cookie state, cache layer, or authenticated flow.","validityConditions":"The URL must be publicly reachable over HTTP or HTTPS. The checker blocks private destinations and follows at most five redirects with bounded timeouts."}},{"slug":"robots-sitemap-checker","title":"Robots.txt + Sitemap Checker","url":"https://toolkitshelf.com/tools/robots-sitemap-checker","category":"Utility Tools","formulaId":"toolkitshelf.formula.robots-sitemap-checker","isCallableViaMcp":false,"lastReviewed":"2026-07-12","inputs":["Site URL","robots.txt","sitemap.xml","Sitemap declarations","Disallow rules","Sitemap URL count"],"resultLabel":"Robots and sitemap discovery report","formula":{"expression":"Discovery report = guarded origin check + /robots.txt fetch + /sitemap.xml fetch + Sitemap declarations + User-agent * Disallow summary + sitemap loc count","label":"Discovery check method","note":"The checker only fetches conventional robots.txt and sitemap.xml URLs for one public origin. It does not crawl the site or simulate a search engine bot."},"example":[{"label":"Robots declaration","value":"Sitemap: https://example.com/sitemap.xml"},{"label":"Blocking rule","value":"User-agent: * with Disallow: / is flagged"},{"label":"Sitemap sample","value":"First sitemap <loc> URLs are shown for quick inspection"}],"sources":[{"href":"https://developers.google.com/search/docs/crawling-indexing/robots/intro","label":"Google Search Central","value":"Documents robots.txt files, rules, and how crawlers use them."},{"href":"https://developers.google.com/search/docs/crawling-indexing/sitemaps/overview","label":"Google Search Central","value":"Documents sitemap formats and sitemap submission guidance."},{"href":"https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API","label":"MDN Web Docs","value":"Documents the Fetch API used for bounded HTTP requests."}],"provenance":{"calculationClass":"external-data","intendedAudience":"Site owners, developers, editors, and launch reviewers checking one public URL at a time.","maintainedBy":"Toolkit Shelf","materiallyReviewedAt":"2026-07-12","primarySource":{"label":"User-provided public URL","sourceDate":"At each run"},"sourceCheckedAt":"2026-07-12","sourceFreshness":"Each result is a point-in-time server request. Rerun the checker after the page, server, cache, or redirect behavior changes.","methodVersion":"toolkitshelf.robots-sitemap-guarded-fetch.v1","relianceBoundary":"The report checks conventional root files and basic directives; it is not a search-engine crawl verdict, complete robots parser, sitemap submission, or index-coverage report.","validityConditions":"The origin, /robots.txt, and /sitemap.xml must be publicly reachable. Results are bounded by redirect, timeout, and response-size limits."}},{"slug":"canonical-meta-robots-checker","title":"Canonical URL + Meta Robots Checker","url":"https://toolkitshelf.com/tools/canonical-meta-robots-checker","category":"Utility Tools","formulaId":"toolkitshelf.formula.canonical-meta-robots-checker","isCallableViaMcp":false,"lastReviewed":"2026-07-12","inputs":["Page URL","HTTP status","Final URL","Title","Canonical URL","Meta robots","X-Robots-Tag","Open Graph URL"],"resultLabel":"Page indexing signal report","formula":{"expression":"Page signal report = guarded HTML fetch + redirect follow + title + canonical + meta robots + googlebot + X-Robots-Tag + og:url checks","label":"Page signal check method","note":"The checker fetches one public HTML URL, follows up to 5 redirects, and blocks local, private, reserved, credentialed, and non-http destinations before each request."},"example":[{"label":"Launch page","value":"Verify canonical URL and robots directives before requesting indexing"},{"label":"Migrated URL","value":"Check whether redirects end on the intended canonical page"},{"label":"SEO support ticket","value":"Capture title, canonical, noindex, and final URL details in one report"}],"sources":[{"href":"https://developers.google.com/search/docs/crawling-indexing/consolidate-duplicate-urls","label":"Google Search Central","value":"Documents canonical URL signals and duplicate URL consolidation guidance."},{"href":"https://developers.google.com/search/docs/crawling-indexing/robots-meta-tag","label":"Google Search Central","value":"Documents robots meta tags and X-Robots-Tag indexing directives."},{"href":"https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API","label":"MDN Web Docs","value":"Documents the Fetch API used for bounded HTTP requests."}],"provenance":{"calculationClass":"external-data","intendedAudience":"Site owners, developers, editors, and launch reviewers checking one public URL at a time.","maintainedBy":"Toolkit Shelf","materiallyReviewedAt":"2026-07-12","primarySource":{"label":"User-provided public URL","sourceDate":"At each run"},"sourceCheckedAt":"2026-07-12","sourceFreshness":"Each result is a point-in-time server request. Rerun the checker after the page, server, cache, or redirect behavior changes.","methodVersion":"toolkitshelf.canonical-meta-static-html.v1","relianceBoundary":"The report is a bounded static-HTML check, not a Google indexing verdict, rendered-DOM test, authenticated crawl, or substitute for Search Console URL Inspection.","validityConditions":"The URL must be publicly reachable over HTTP or HTTPS. Results cover the fetched response, headers, and static HTML within redirect, timeout, and body-size limits."}},{"slug":"social-preview-checker","title":"Open Graph + Twitter Card Checker","url":"https://toolkitshelf.com/tools/social-preview-checker","category":"Utility Tools","formulaId":"toolkitshelf.formula.social-preview-checker","isCallableViaMcp":false,"lastReviewed":"2026-07-12","inputs":["Page URL","HTTP status","Final URL","Title","Meta description","Open Graph tags","Twitter Card tags","Preview image"],"resultLabel":"Social preview metadata report","formula":{"expression":"Share preview report = guarded HTML fetch + redirect follow + title + meta description + Open Graph tags + Twitter Card tags + preview image checks","label":"Social preview check method","note":"The checker fetches one public HTML URL, follows up to 5 redirects, and blocks local, private, reserved, credentialed, and non-http destinations before each request."},"example":[{"label":"Launch page","value":"Verify og:image and social title before posting a new page"},{"label":"Newsletter link","value":"Check whether the shared URL has a readable title and description"},{"label":"Campaign QA","value":"Capture final URL, Open Graph, and Twitter Card fields in one handoff"}],"sources":[{"href":"https://ogp.me/","label":"Open Graph protocol","value":"Documents the core Open Graph metadata fields used by social previews."},{"href":"https://developer.x.com/en/docs/x-for-websites/cards/overview/markup","label":"X Developer Platform","value":"Documents Twitter Card markup fields used for card previews."},{"href":"https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API","label":"MDN Web Docs","value":"Documents the Fetch API used for bounded HTTP requests."}],"provenance":{"calculationClass":"external-data","intendedAudience":"Site owners, developers, editors, and launch reviewers checking one public URL at a time.","maintainedBy":"Toolkit Shelf","materiallyReviewedAt":"2026-07-12","primarySource":{"label":"User-provided public URL","sourceDate":"At each run"},"sourceCheckedAt":"2026-07-12","sourceFreshness":"Each result is a point-in-time server request. Rerun the checker after the page, server, cache, or redirect behavior changes.","methodVersion":"toolkitshelf.social-preview-static-html.v1","relianceBoundary":"The report reads static Open Graph and card metadata; it cannot reproduce every platform cache, crop, scraper user agent, or JavaScript-rendered preview.","validityConditions":"Preview tags must exist in the fetched static HTML. Platform caches, client rendering, authentication, blocking, and truncation can change real previews."}},{"slug":"structured-data-checker","title":"JSON-LD Structured Data Checker","url":"https://toolkitshelf.com/tools/structured-data-checker","category":"Utility Tools","formulaId":"toolkitshelf.formula.structured-data-checker","isCallableViaMcp":false,"lastReviewed":"2026-07-12","inputs":["Page URL","HTTP status","Final URL","JSON-LD scripts","Parse validity","Schema @type values","Graph nodes","Structured data warnings"],"resultLabel":"JSON-LD structured data report","formula":{"expression":"Structured data report = guarded HTML fetch + redirect follow + application/ld+json extraction + JSON parse + @type and @graph summary","label":"Structured data check method","note":"The checker fetches one public HTML URL, follows up to 5 redirects, and blocks local, private, reserved, credentialed, and non-http destinations before each request."},"example":[{"label":"Tool page","value":"Confirm FAQPage, WebApplication, or BreadcrumbList markup parses cleanly"},{"label":"Article page","value":"Check Article, WebPage, and BreadcrumbList JSON-LD before publication"},{"label":"SEO handoff","value":"Copy script counts, detected types, and parse warnings into a launch ticket"}],"sources":[{"href":"https://developers.google.com/search/docs/appearance/structured-data/intro-structured-data","label":"Google Search Central","value":"Documents structured data for Google Search and rich result eligibility guidance."},{"href":"https://schema.org/","label":"Schema.org","value":"Documents schema vocabulary types and properties used in structured data."},{"href":"https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/parse","label":"MDN Web Docs","value":"Documents JSON syntax and parsing behavior used to validate JSON-LD blocks."}],"provenance":{"calculationClass":"external-data","intendedAudience":"Site owners, developers, editors, and launch reviewers checking one public URL at a time.","maintainedBy":"Toolkit Shelf","materiallyReviewedAt":"2026-07-12","primarySource":{"label":"User-provided public URL","sourceDate":"At each run"},"sourceCheckedAt":"2026-07-12","sourceFreshness":"Each result is a point-in-time server request. Rerun the checker after the page, server, cache, or redirect behavior changes.","methodVersion":"toolkitshelf.jsonld-static-html.v1","relianceBoundary":"The report parses JSON-LD syntax and visible types; it is not Google Rich Results eligibility, schema-policy approval, or a rendered-DOM validator.","validityConditions":"JSON-LD must exist in the fetched static HTML and be valid JSON. Client-injected, authenticated, blocked, or truncated markup may be absent."}},{"slug":"http-header-cache-checker","title":"HTTP Headers + Cache Checker","url":"https://toolkitshelf.com/tools/http-header-cache-checker","category":"Utility Tools","formulaId":"toolkitshelf.formula.http-header-cache-checker","isCallableViaMcp":false,"lastReviewed":"2026-07-12","inputs":["URL to check","HTTP status","Final URL","Cache-Control","CDN cache headers","Content type","Compression","Security headers"],"resultLabel":"HTTP header and cache report","formula":{"expression":"Header report = guarded request + redirect follow + final response status + selected cache, content, indexing, and policy headers","label":"Header check method","note":"The checker fetches one public URL, follows up to 5 redirects, and blocks local, private, reserved, credentialed, and non-http destinations before each request."},"example":[{"label":"Launch page","value":"Verify Cache-Control, content type, and policy headers before release"},{"label":"CDN debugging","value":"Compare CDN cache status headers against expected cache behavior"},{"label":"SEO QA","value":"Check whether X-Robots-Tag noindex is present on the final response"}],"sources":[{"href":"https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Headers","label":"MDN Web Docs","value":"Documents HTTP headers and how response metadata is represented."},{"href":"https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Headers/Cache-Control","label":"MDN Web Docs","value":"Documents Cache-Control directives used for browser and shared cache behavior."},{"href":"https://developer.mozilla.org/en-US/docs/Web/Security/Practical_implementation_guides","label":"MDN Web Docs","value":"Documents common HTTP security response headers."}],"provenance":{"calculationClass":"external-data","intendedAudience":"Site owners, developers, editors, and launch reviewers checking one public URL at a time.","maintainedBy":"Toolkit Shelf","materiallyReviewedAt":"2026-07-12","primarySource":{"label":"User-provided public URL","sourceDate":"At each run"},"sourceCheckedAt":"2026-07-12","sourceFreshness":"Each result is a point-in-time server request. Rerun the checker after the page, server, cache, or redirect behavior changes.","methodVersion":"toolkitshelf.http-header-guarded-fetch.v1","relianceBoundary":"The report describes one observed response and does not prove every region, edge cache, browser, request method, or authenticated state behaves the same way.","validityConditions":"The URL must be publicly reachable over HTTP or HTTPS. Header values reflect the server response observed by the checker at that moment."}},{"slug":"heading-structure-checker","title":"Heading Structure + H1 Checker","url":"https://toolkitshelf.com/tools/heading-structure-checker","category":"Utility Tools","formulaId":"toolkitshelf.formula.heading-structure-checker","isCallableViaMcp":false,"lastReviewed":"2026-07-12","inputs":["Page URL","HTTP status","Final URL","H1 count","Heading outline","Skipped levels","Duplicate headings"],"resultLabel":"Heading structure and H1 report","formula":{"expression":"Heading report = guarded HTML fetch + redirect follow + h1-h6 extraction + outline order + H1, duplicate, empty, and skipped-level checks","label":"Heading extraction method","note":"The checker fetches one public HTML URL, follows up to 5 redirects, and blocks local, private, reserved, credentialed, and non-http destinations before each request."},"example":[{"label":"Launch page","value":"Confirm one clear H1 and a readable H2/H3 outline before publishing"},{"label":"Template QA","value":"Find repeated headings, empty headings, and skipped levels caused by layout components"},{"label":"Content refresh","value":"Copy a heading outline for editorial review before rewriting a page"}],"sources":[{"href":"https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Elements/Heading_Elements","label":"MDN Web Docs","value":"Documents HTML heading elements h1 through h6 and their intended structure."},{"href":"https://www.w3.org/WAI/tutorials/page-structure/headings/","label":"W3C WAI","value":"Explains how headings communicate page structure to users and assistive technologies."},{"href":"https://developers.google.com/search/docs/fundamentals/creating-helpful-content","label":"Google Search Central","value":"Recommends clear, descriptive page titles and headings as part of helpful page content."}],"provenance":{"calculationClass":"external-data","intendedAudience":"Site owners, developers, editors, and launch reviewers checking one public URL at a time.","maintainedBy":"Toolkit Shelf","materiallyReviewedAt":"2026-07-12","primarySource":{"label":"User-provided public URL","sourceDate":"At each run"},"sourceCheckedAt":"2026-07-12","sourceFreshness":"Each result is a point-in-time server request. Rerun the checker after the page, server, cache, or redirect behavior changes.","methodVersion":"toolkitshelf.heading-static-html.v1","relianceBoundary":"The report checks heading markup in one fetched HTML response; it is not a rendered accessibility audit, content-quality verdict, or full-site crawl.","validityConditions":"The public response must contain the relevant headings in static HTML. Client-rendered, authenticated, blocked, or truncated content may be absent."}},{"slug":"image-alt-text-checker","title":"Image Alt Text Checker","url":"https://toolkitshelf.com/tools/image-alt-text-checker","category":"Utility Tools","formulaId":"toolkitshelf.formula.image-alt-text-checker","isCallableViaMcp":false,"lastReviewed":"2026-07-12","inputs":["Page URL","HTTP status","Final URL","Image tags","Alt attributes","Image src","Dimensions","Loading hints"],"resultLabel":"Image alt text report","formula":{"expression":"Image report = guarded HTML fetch + redirect follow + img tag extraction + alt, duplicate, decorative, dimension, srcset, loading, and decoding checks","label":"Image alt extraction method","note":"The checker fetches one public HTML URL, follows up to 5 redirects, and blocks local, private, reserved, credentialed, and non-http destinations before each request."},"example":[{"label":"Launch page","value":"Find missing alt attributes and empty alt text before publishing"},{"label":"Template QA","value":"Check whether repeated component images create duplicate alt text"},{"label":"Content refresh","value":"Copy image src and alt details into an editorial QA handoff"}],"sources":[{"href":"https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Elements/img","label":"MDN Web Docs","value":"Documents the HTML image element and attributes such as alt, src, srcset, loading, and decoding."},{"href":"https://www.w3.org/WAI/tutorials/images/decision-tree/","label":"W3C WAI","value":"Provides an alt decision tree for deciding when images need text alternatives."},{"href":"https://developers.google.com/search/docs/appearance/google-images","label":"Google Search Central","value":"Recommends descriptive alt text and image context for search and accessibility."}],"provenance":{"calculationClass":"external-data","intendedAudience":"Site owners, developers, editors, and launch reviewers checking one public URL at a time.","maintainedBy":"Toolkit Shelf","materiallyReviewedAt":"2026-07-12","primarySource":{"label":"User-provided public URL","sourceDate":"At each run"},"sourceCheckedAt":"2026-07-12","sourceFreshness":"Each result is a point-in-time server request. Rerun the checker after the page, server, cache, or redirect behavior changes.","methodVersion":"toolkitshelf.image-alt-static-html.v1","relianceBoundary":"The report inventories image markup in one response; it cannot decide whether alt text is contextually useful or replace an accessibility review with assistive technology.","validityConditions":"Images and alt attributes must exist in the fetched static HTML. Client-rendered, lazy-injected, authenticated, blocked, or truncated content may be absent."}},{"slug":"page-links-anchor-checker","title":"Page Links + Anchor Text Checker","url":"https://toolkitshelf.com/tools/page-links-anchor-checker","category":"Utility Tools","formulaId":"toolkitshelf.formula.page-links-anchor-checker","isCallableViaMcp":false,"lastReviewed":"2026-07-12","inputs":["Page URL","HTTP status","Final URL","Anchor links","Anchor text","Internal links","External links","Rel attributes"],"resultLabel":"Page links and anchor text report","formula":{"expression":"Link report = guarded HTML fetch + redirect follow + anchor tag extraction + href classification + anchor text and rel attribute checks","label":"Link extraction method","note":"The checker fetches one public HTML URL, follows up to 5 redirects, and blocks local, private, reserved, credentialed, and non-http destinations before each request."},"example":[{"label":"Launch page","value":"Check whether key navigation and CTA links are present with readable anchor text"},{"label":"Affiliate page","value":"Review external links and rel=sponsored or nofollow usage before publishing"},{"label":"Content QA","value":"Find empty anchors, duplicate hrefs, and target=_blank links missing rel=noopener"}],"sources":[{"href":"https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Elements/a","label":"MDN Web Docs","value":"Documents the HTML anchor element, href attribute, target behavior, and rel usage."},{"href":"https://developers.google.com/search/docs/crawling-indexing/qualify-outbound-links","label":"Google Search Central","value":"Documents link qualification values such as nofollow, sponsored, and ugc."},{"href":"https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Attributes/rel/noopener","label":"MDN Web Docs","value":"Documents noopener behavior for safer new-tab links."}],"provenance":{"calculationClass":"external-data","intendedAudience":"Site owners, developers, editors, and launch reviewers checking one public URL at a time.","maintainedBy":"Toolkit Shelf","materiallyReviewedAt":"2026-07-12","primarySource":{"label":"User-provided public URL","sourceDate":"At each run"},"sourceCheckedAt":"2026-07-12","sourceFreshness":"Each result is a point-in-time server request. Rerun the checker after the page, server, cache, or redirect behavior changes.","methodVersion":"toolkitshelf.page-links-static-html.v1","relianceBoundary":"The report inventories one page response and does not replace a rendered interaction test, full crawl, link-status audit, or editorial review of anchor meaning.","validityConditions":"Links must appear in the fetched static HTML. Client-rendered, authenticated, blocked, or truncated links may be absent from the result."}},{"slug":"qr-code-generator","title":"QR Code Generator","url":"https://toolkitshelf.com/tools/qr-code-generator","category":"Utility Tools","formulaId":"toolkitshelf.formula.qr-code-generator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Text or URL","WiFi network","Contact card","Error correction","Colors","Image size"],"resultLabel":"PNG and SVG QR code","formula":{"expression":"QR code = encoded payload + error correction level + quiet zone + module colors + output size","label":"QR generation method","note":"Scan reliability depends on payload length, contrast, quiet zone, print size, surface quality, and the scanner being used."},"example":[{"label":"URL QR","value":"Menu, booking link, landing page, or coupon URL"},{"label":"WiFi QR","value":"Network name, password, security type, and hidden flag"},{"label":"Contact QR","value":"vCard-style name, organization, phone, email, and website"}],"sources":[{"href":"https://www.qrcode.com/en/about/standards.html","label":"DENSO WAVE","value":"Documents QR Code capacity, symbol versions, and ISO/IEC 18004 standardization."},{"href":"https://www.qrcode.com/en/about/error_correction.html","label":"DENSO WAVE","value":"Explains QR Code error correction levels and the tradeoff between resilience and code size."},{"href":"https://github.com/soldair/node-qrcode","label":"node-qrcode","value":"Open-source QR rendering package used for browser-side PNG and SVG output."}]},{"slug":"keyword-density-calculator","title":"Keyword Density Calculator","url":"https://toolkitshelf.com/tools/keyword-density-calculator","category":"Text and Writing Tools","formulaId":"toolkitshelf.formula.keyword-density-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Text","Keyword or phrase"],"resultLabel":"Keyword density","formula":{"expression":"Keyword density = keyword occurrences / total words x 100","label":"Keyword density formula","note":"Density is a rough editing check, not a ranking target. Helpful content matters more than forcing a percentage."},"example":[{"label":"Words","value":"850"},{"label":"Keyword uses","value":"9"},{"label":"Density","value":"1.1%"}],"sources":[]},{"slug":"meta-description-length-checker","title":"Meta Description Length Checker","url":"https://toolkitshelf.com/tools/meta-description-length-checker","category":"Text and Writing Tools","formulaId":"toolkitshelf.formula.meta-description-length-checker","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Meta description text"],"resultLabel":"Description length","formula":{"expression":"Remaining characters = target limit - description characters","label":"Description length formula","note":"Snippet display varies by query, device, and search engine. This is a drafting check, not a guarantee."},"example":[{"label":"Draft length","value":"148 characters"},{"label":"Planning range","value":"120 - 160 characters"},{"label":"Status","value":"Likely concise"}],"sources":[]},{"slug":"hashtag-counter","title":"Hashtag Counter","url":"https://toolkitshelf.com/tools/hashtag-counter","category":"Text and Writing Tools","formulaId":"toolkitshelf.formula.hashtag-counter","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Caption or post text"],"resultLabel":"Hashtag count","formula":{"expression":"Hashtag count = number of # tags detected in the text","label":"Hashtag count method","note":"The tool also shows unique hashtags and repeated hashtags so crowded captions are easier to clean up."},"example":[{"label":"Hashtags","value":"8 total"},{"label":"Unique","value":"7 unique"},{"label":"Repeated","value":"1 repeat"}],"sources":[]},{"slug":"youtube-title-length-checker","title":"YouTube Title Length Checker","url":"https://toolkitshelf.com/tools/youtube-title-length-checker","category":"Text and Writing Tools","formulaId":"toolkitshelf.formula.youtube-title-length-checker","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Video title"],"resultLabel":"Title length","formula":{"expression":"Remaining characters = 100 - title characters","label":"Title length formula","note":"YouTube interfaces and search surfaces can truncate titles visually, so the count is a planning check."},"example":[{"label":"Planning limit","value":"100 characters"},{"label":"Draft","value":"72 characters"},{"label":"Remaining","value":"28 characters"}],"sources":[]},{"slug":"linkedin-post-length-checker","title":"LinkedIn Post Length Checker","url":"https://toolkitshelf.com/tools/linkedin-post-length-checker","category":"Text and Writing Tools","formulaId":"toolkitshelf.formula.linkedin-post-length-checker","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["LinkedIn post text"],"resultLabel":"Post length","formula":{"expression":"Remaining characters = character limit - post characters","label":"LinkedIn length formula","note":"The default planning limit is 3,000 characters. Visual truncation can still happen earlier in feeds."},"example":[{"label":"Planning limit","value":"3,000 characters"},{"label":"Draft","value":"1,240 characters"},{"label":"Status","value":"Readable post length"}],"sources":[]},{"slug":"tiktok-caption-length-checker","title":"TikTok Caption Length Checker","url":"https://toolkitshelf.com/tools/tiktok-caption-length-checker","category":"Text and Writing Tools","formulaId":"toolkitshelf.formula.tiktok-caption-length-checker","isCallableViaMcp":false,"lastReviewed":"2026-07-13","inputs":["TikTok caption text"],"resultLabel":"Caption length","formula":{"expression":"Remaining characters = character limit - caption characters","label":"Caption length formula","note":"The default is an editable 2,200-character planning threshold, not a verified current TikTok maximum. Confirm the current limit in the app before publishing."},"example":[{"label":"Editable planning threshold","value":"2,200 characters"},{"label":"Caption","value":"340 characters"},{"label":"Hashtags","value":"5 tags"}],"sources":[],"provenance":{"calculationClass":"deterministic","intendedAudience":"Creators checking caption length against an editable planning threshold before publishing in TikTok.","maintainedBy":"Toolkit Shelf","materiallyReviewedAt":"2026-07-13","methodVersion":"toolkitshelf.tiktok-caption-editable-threshold.v1","primarySource":{"label":"User-confirmed TikTok in-app limit","sourceDate":"Confirm at time of use"},"relianceBoundary":"The default 2,200-character value is a Toolkit Shelf planning threshold, not a verified current TikTok maximum, publishing guarantee, display-preview guarantee, or platform policy statement.","sourceCheckedAt":"2026-07-13","sourceFreshness":"No volatile platform maximum is asserted. The threshold remains editable so users can match the current limit shown by TikTok at the time of posting.","validityConditions":"The count includes every character in the entered caption. Confirm the current TikTok limit and relevant app surface, then edit the threshold before relying on the remaining-character result."}},{"slug":"startup-runway-calculator","title":"Cash Runway Calculator","url":"https://toolkitshelf.com/tools/startup-runway-calculator","category":"Business Tools","formulaId":"toolkitshelf.formula.startup-runway-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Cash balance","Monthly revenue","Monthly expenses","Expense change %"],"resultLabel":"Months of runway","formula":{"expression":"Runway = cash balance / (monthly expenses - monthly revenue)","label":"Runway formula","note":"If monthly revenue is greater than expenses, the business is default alive at the current run rate."},"example":[{"label":"Cash balance","value":"$750,000"},{"label":"Monthly revenue","value":"$65,000"},{"label":"Monthly expenses","value":"$145,000"},{"label":"Expense change","value":"0%"},{"label":"Adjusted expenses","value":"$145,000"},{"label":"Net burn","value":"$80,000/month"},{"label":"Monthly position","value":"-$80,000"},{"label":"Runway","value":"9.4 months"}],"sources":[{"href":"https://www.sba.gov/business-guide/manage-your-business/manage-your-finances","label":"U.S. Small Business Administration","value":"Lists available cash, accounts receivable, accounts payable, payroll, and bank reconciliation as finance areas to manage."}]},{"slug":"small-business-cash-flow-planner","title":"Small Business Cash Flow Planner","url":"https://toolkitshelf.com/tools/small-business-cash-flow-planner","category":"Business Tools","formulaId":"toolkitshelf.formula.small-business-cash-flow-planner","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Starting cash","Monthly revenue","Monthly expenses","Owner draw","Tax reserve % of revenue","Accounts receivable","Accounts payable","One-time costs due soon"],"resultLabel":"Small business cash flow read","formula":{"expression":"Adjusted cash = starting cash + accounts receivable - accounts payable - one-time costs; monthly net cash = revenue - expenses - owner draw - tax reserve","label":"Cash flow planner formula","note":"This is a cash-timing planner, not an accounting profit statement."},"example":[{"label":"Starting cash","value":"$42,000"},{"label":"Monthly revenue","value":"$24,000"},{"label":"Adjusted cash","value":"$52,000"},{"label":"Monthly net cash","value":"$1,200"},{"label":"90 day cash","value":"$55,600"},{"label":"Status","value":"Cash growing"}],"sources":[{"href":"https://www.sba.gov/business-guide/manage-your-business/manage-your-finances","label":"U.S. Small Business Administration","value":"Provides guidance on managing business finances, cash flow, bookkeeping, and working with business numbers."},{"href":"https://www.irs.gov/businesses/small-businesses-self-employed/self-employed-individuals-tax-center","label":"Internal Revenue Service","value":"Provides self-employment tax guidance for people who work for themselves."}]},{"slug":"profit-margin-calculator","title":"Profit Margin Calculator","url":"https://toolkitshelf.com/tools/profit-margin-calculator","category":"Business Tools","formulaId":"toolkitshelf.formula.profit-margin-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Revenue","Cost of goods","Operating expenses","Target net margin"],"resultLabel":"Profit margin","formula":{"expression":"Gross margin = (revenue - cost of goods) / revenue x 100; net margin = (revenue - cost of goods - expenses) / revenue x 100; markup = (revenue - cost of goods) / cost of goods x 100","label":"Profit margin formulas","note":"Gross margin looks only at direct costs. Net margin also includes operating expenses."},"example":[{"label":"Revenue","value":"$10,000"},{"label":"Cost of goods","value":"$4,200"},{"label":"Operating expenses","value":"$1,800"},{"label":"Gross profit","value":"$5,800"},{"label":"Net profit","value":"$4,000"},{"label":"Net margin","value":"40%"},{"label":"Revenue for target margin","value":"$8,571.43"}],"sources":[{"href":"https://www.sba.gov/business-guide/plan-your-business/calculate-your-startup-costs/break-even-point","label":"U.S. Small Business Administration","value":"Explains break-even analysis, contribution margin, and how pricing affects profitability."},{"href":"https://www.sba.gov/business-guide/manage-your-business/marketing-sales","label":"U.S. Small Business Administration","value":"Notes that marketing plans should include pricing strategy and promotions."}]},{"slug":"freelance-rate-calculator","title":"Freelance Rate Calculator","url":"https://toolkitshelf.com/tools/freelance-rate-calculator","category":"Business Tools","formulaId":"toolkitshelf.formula.freelance-rate-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Take-home income goal","Business expenses","Tax reserve","Billable hours","Weeks off"],"resultLabel":"Required rate","formula":{"expression":"Required annual revenue = take-home goal / (1 - tax rate) + business expenses; hourly rate = required annual revenue / annual billable hours","label":"Freelance rate formula","note":"Billable hours are usually lower than total working hours because admin, sales, revisions, and time off are not always billable."},"example":[{"label":"Take-home goal","value":"$90,000"},{"label":"Expenses","value":"$12,000"},{"label":"Tax reserve","value":"25%"},{"label":"Billable hours","value":"1,150 / year"}],"sources":[{"href":"https://www.irs.gov/businesses/small-businesses-self-employed/self-employed-individuals-tax-center","label":"Internal Revenue Service","value":"Explains that self-employed individuals generally must pay self-employment tax as well as income tax."},{"href":"https://www.sba.gov/business-guide/manage-your-business/marketing-sales","label":"U.S. Small Business Administration","value":"Notes that marketing plans should include pricing strategy and promotions."}]},{"slug":"invoice-generator","title":"Invoice Generator","url":"https://toolkitshelf.com/tools/invoice-generator","category":"Business Tools","formulaId":"toolkitshelf.formula.invoice-generator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Invoice number","Issue date","Sender","Client","Currency","Line items","Quantity","Rate","Payment terms (days)","Payment notes","Discount","Tax"],"resultLabel":"Invoice total","formula":{"expression":"Balance due = subtotal - discount + tax; subtotal = sum(quantity x rate); tax = (subtotal - discount) x tax rate","label":"Invoice total formula","note":"This generator calculates totals. It does not replace accounting, tax, or legal invoice requirements in your jurisdiction."},"example":[{"label":"Consulting","value":"10 x $125"},{"label":"Project work","value":"1 x $750"},{"label":"Payment terms","value":"Net 30"},{"label":"Due date","value":"30 days after issue"},{"label":"Tax","value":"8%"},{"label":"Balance due","value":"$2,160"}],"sources":[{"href":"https://www.irs.gov/businesses/small-businesses-self-employed/what-kind-of-records-should-i-keep","label":"Internal Revenue Service","value":"Explains that business recordkeeping should clearly show income and expenses and include supporting documents."},{"href":"https://www.irs.gov/businesses/small-businesses-self-employed/self-employed-individuals-tax-center","label":"Internal Revenue Service","value":"Summarizes federal tax obligations for self-employed individuals and independent contractors."}]},{"slug":"net-payment-terms-calculator","title":"Net Payment Terms Calculator","url":"https://toolkitshelf.com/tools/net-payment-terms-calculator","category":"Business Tools","formulaId":"toolkitshelf.formula.net-payment-terms-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Invoice amount","Net terms days","Expected delay","Annual cash cost","Monthly late fee"],"resultLabel":"Payment wait and cash cost","formula":{"expression":"Cash cost = invoice amount x annual cash cost x payment wait days / 365","label":"Payment terms cost formula","note":"This is a cash-flow planning estimate. Contract terms, collection risk, local rules, and client approval processes can change the real outcome."},"example":[{"label":"Invoice amount","value":"$5,000"},{"label":"Expected payment wait","value":"37 days"},{"label":"Cash cost of waiting","value":"$60.82"},{"label":"Late fee amount","value":"$75.00"},{"label":"Net after cash cost","value":"$4,939.18"}],"sources":[]},{"slug":"agency-margin-calculator","title":"Agency Margin Calculator","url":"https://toolkitshelf.com/tools/agency-margin-calculator","category":"Business Tools","formulaId":"toolkitshelf.formula.agency-margin-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Monthly revenue","Delivery hours","Blended cost per hour","Pass-through costs","Monthly overhead"],"resultLabel":"Agency margin","formula":{"expression":"Gross margin = (revenue - labor cost - pass-through costs) / revenue x 100","label":"Agency margin formula","note":"Operating margin subtracts overhead after delivery cost. Use loaded labor cost for a cleaner estimate."},"example":[{"label":"Monthly revenue","value":"$28,000"},{"label":"Labor cost","value":"$10,400"},{"label":"Delivery cost","value":"$14,600"},{"label":"Gross margin","value":"47.9%"},{"label":"Operating margin","value":"34.3%"},{"label":"Operating profit","value":"$9,600"}],"sources":[]},{"slug":"retainer-pricing-calculator","title":"Retainer Pricing Calculator","url":"https://toolkitshelf.com/tools/retainer-pricing-calculator","category":"Business Tools","formulaId":"toolkitshelf.formula.retainer-pricing-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Monthly delivery hours","Delivery cost per hour","Monthly overhead allocation","Target margin","Scope buffer"],"resultLabel":"Suggested retainer","formula":{"expression":"Suggested retainer = buffered cost base / (1 - target margin)","label":"Retainer pricing formula","note":"Buffered cost base includes delivery cost, scope buffer, and overhead allocation. Final pricing also depends on value, risk, and contract terms."},"example":[{"label":"Monthly delivery hours","value":"42"},{"label":"Target margin","value":"45%"},{"label":"Suggested retainer","value":"$8,048"},{"label":"Effective hourly revenue","value":"$191.62"},{"label":"Expected profit","value":"$3,622"},{"label":"Buffered delivery cost","value":"$3,864"}],"sources":[]},{"slug":"client-profitability-calculator","title":"Client Profitability Calculator","url":"https://toolkitshelf.com/tools/client-profitability-calculator","category":"Business Tools","formulaId":"toolkitshelf.formula.client-profitability-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Monthly client revenue","Delivery hours","Admin/support hours","Loaded hourly cost","Tools and vendors","Pass-through costs"],"resultLabel":"Client profit","formula":{"expression":"Client profit = monthly revenue - labor cost - tools and vendors - pass-through costs","label":"Client profitability formula","note":"Include support and admin time so the result reflects the true cost of serving the client."},"example":[{"label":"Monthly client revenue","value":"$9,000"},{"label":"Total hours","value":"56"},{"label":"Client profit","value":"$3,430"},{"label":"Revenue per hour","value":"$160.71"},{"label":"Profit per hour","value":"$61.25"},{"label":"Total modeled cost","value":"$5,570"}],"sources":[]},{"slug":"burn-multiple-calculator","title":"Burn Multiple Calculator","url":"https://toolkitshelf.com/tools/burn-multiple-calculator","category":"Business Tools","formulaId":"toolkitshelf.formula.burn-multiple-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Monthly net burn","Period months","Starting ARR","Ending ARR"],"resultLabel":"Burn multiple","formula":{"expression":"Burn multiple = total net burn / net new ARR","label":"Burn multiple formula","note":"Use the same period for burn and ARR change. This simplified metric does not explain why burn or growth changed."},"example":[{"label":"Monthly net burn","value":"$85,000"},{"label":"Period months","value":"6"},{"label":"Total burn","value":"$510,000"},{"label":"Net new ARR","value":"$550,000"},{"label":"ARR growth rate","value":"61.1%"},{"label":"Burn multiple","value":"0.93x"}],"sources":[]},{"slug":"startup-dilution-calculator","title":"Startup Dilution Calculator","url":"https://toolkitshelf.com/tools/startup-dilution-calculator","category":"Business Tools","formulaId":"toolkitshelf.formula.startup-dilution-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Pre-money valuation","Investment amount","Option pool increase","Current ownership"],"resultLabel":"Ownership after dilution","formula":{"expression":"Investor ownership = investment / (pre-money valuation + investment)","label":"Startup dilution formula","note":"This simplified calculator does not model SAFEs, notes, preferences, pro rata rights, anti-dilution clauses, or detailed cap table terms."},"example":[{"label":"Pre-money valuation","value":"$8,000,000"},{"label":"Investment","value":"$1,500,000"},{"label":"Investor ownership","value":"15.79%"}],"sources":[]},{"slug":"break-even-calculator","title":"Break-Even Calculator","url":"https://toolkitshelf.com/tools/break-even-calculator","category":"Business Tools","formulaId":"toolkitshelf.formula.break-even-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Fixed costs","Price per unit","Variable cost per unit","Target profit"],"resultLabel":"Break-even units","formula":{"expression":"Break-even units = fixed costs / (price per unit - variable cost per unit)","label":"Break-even formula","note":"The difference between price and variable cost is the contribution margin per unit."},"example":[{"label":"Fixed costs","value":"$12,000"},{"label":"Contribution margin per unit","value":"$48"},{"label":"Contribution margin rate","value":"60.8%"},{"label":"Break-even units","value":"250"},{"label":"Break-even revenue","value":"$19,750"},{"label":"Units for target profit","value":"355"}],"sources":[{"href":"https://www.sba.gov/business-guide/plan-your-business/calculate-your-startup-costs/break-even-point","label":"U.S. Small Business Administration","value":"Explains break-even analysis, contribution margin, and how pricing affects profitability."}]},{"slug":"mrr-calculator","title":"MRR Calculator","url":"https://toolkitshelf.com/tools/mrr-calculator","category":"Business Tools","formulaId":"toolkitshelf.formula.mrr-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Starting MRR","New customers","Average revenue per account","Expansion MRR","Contraction MRR","Churned MRR"],"resultLabel":"Ending MRR","formula":{"expression":"Ending MRR = starting MRR + new MRR + expansion MRR - contraction MRR - churned MRR","label":"MRR formula","note":"Use the same monthly period for all inputs so new, expansion, contraction, and churn are comparable."},"example":[{"label":"Starting MRR","value":"$42,000"},{"label":"New-logo MRR","value":"$3,040"},{"label":"Net new MRR","value":"$2,090"},{"label":"Ending MRR","value":"$44,090"},{"label":"MRR growth rate","value":"5.0%"},{"label":"ARR run rate","value":"$529,080"}],"sources":[]},{"slug":"churn-rate-calculator","title":"Churn Rate Calculator","url":"https://toolkitshelf.com/tools/churn-rate-calculator","category":"Business Tools","formulaId":"toolkitshelf.formula.churn-rate-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Starting customers","Lost customers","Starting MRR","Churned MRR"],"resultLabel":"Churn rate","formula":{"expression":"Customer churn = lost customers / starting customers x 100","label":"Churn rate formula","note":"Revenue churn uses churned MRR divided by starting MRR for the same period."},"example":[{"label":"Starting customers","value":"820"},{"label":"Lost customers","value":"38"},{"label":"Customer churn","value":"4.63%"},{"label":"Revenue churn","value":"6.41%"},{"label":"Retained customers","value":"782"},{"label":"Retained MRR","value":"$59,900"}],"sources":[]},{"slug":"ltv-cac-calculator","title":"LTV CAC Calculator","url":"https://toolkitshelf.com/tools/ltv-cac-calculator","category":"Business Tools","formulaId":"toolkitshelf.formula.ltv-cac-calculator","isCallableViaMcp":true,"lastReviewed":"2026-06-06","mcpTool":"calculate_ltv_cac","inputs":["ARPA / monthly revenue","Gross margin","Monthly churn","CAC"],"resultLabel":"LTV / CAC ratio","formula":{"expression":"LTV = ARPA x gross margin / monthly churn; LTV/CAC = LTV / CAC","label":"LTV/CAC formula","note":"This is a simplified subscription estimate. It assumes churn is stable and uses gross profit, not revenue, for LTV."},"example":[{"label":"ARPA","value":"$120"},{"label":"Gross margin","value":"78%"},{"label":"Monthly churn","value":"4%"},{"label":"Gross profit per month","value":"$93.60"},{"label":"Customer lifetime months","value":"25.0"},{"label":"Estimated LTV","value":"$2,340"},{"label":"LTV/CAC","value":"3.6x"},{"label":"CAC payback","value":"6.9 months"}],"sources":[]},{"slug":"contractor-day-rate-calculator","title":"Contractor Day Rate Calculator","url":"https://toolkitshelf.com/tools/contractor-day-rate-calculator","category":"Business Tools","formulaId":"toolkitshelf.formula.contractor-day-rate-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Take-home income","Tax reserve","Annual expenses","Billable days"],"resultLabel":"Contractor day rate","formula":{"expression":"Day rate = (target take-home / (1 - tax reserve) + expenses) / billable days","label":"Day rate formula","note":"Billable days should exclude holidays, sick time, admin time, sales time, and gaps between projects."},"example":[{"label":"Take-home goal","value":"$120,000"},{"label":"Billable days","value":"165"},{"label":"Day rate","value":"$1,095"}],"sources":[]},{"slug":"tiktok-performance-analyzer","title":"TikTok Performance Analyzer","url":"https://toolkitshelf.com/tools/tiktok-performance-analyzer","category":"Social Media Tools","formulaId":"toolkitshelf.formula.tiktok-performance-analyzer","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Followers","Current views","Likes","Comments","Shares","Saves","Hours since posted","Usual views per post"],"resultLabel":"TikTok performance read","formula":{"expression":"Engagement by views = interactions / views x 100; intent actions per 1,000 views = (saves + shares) / views x 1,000","label":"TikTok performance formulas","note":"The analyzer also compares current views with the usual views per post and estimates a 24-hour view range from current pace."},"example":[{"label":"Current views","value":"128,000"},{"label":"Usual views per post","value":"48,000"},{"label":"Intent actions","value":"2,100 saves + shares"},{"label":"Performance read","value":"High-intent post"}],"sources":[{"href":"https://support.tiktok.com/en/using-tiktok/creating-videos/tiktok-studio/","label":"TikTok Help Center","value":"Explains that TikTok Studio includes post analytics such as views, likes, shares, and other performance metrics."}]},{"slug":"tiktok-post-diagnostic-tool","title":"TikTok Post Diagnostic Tool","url":"https://toolkitshelf.com/tools/tiktok-post-diagnostic-tool","category":"Social Media Tools","formulaId":"toolkitshelf.formula.tiktok-post-diagnostic-tool","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Post goal","Post format","Followers","Usual views per post","Current views","Hours since posted","Likes","Comments","Shares","Saves","Profile visits"],"resultLabel":"TikTok post diagnostic","formula":{"expression":"Diagnostic score = weighted reach, intent, discussion, and conversion signals based on the selected post goal","label":"TikTok diagnostic method","note":"Reach uses baseline views and view velocity. Intent uses saves and shares. Discussion uses comments. Conversion uses profile visits or link taps."},"example":[{"label":"Goal","value":"Saves / shares"},{"label":"Current views","value":"86,000 in 10 hours"},{"label":"Usual views per post","value":"48,000"},{"label":"Diagnostic","value":"Double down"}],"sources":[{"href":"https://support.tiktok.com/en/using-tiktok/creating-videos/tiktok-studio/","label":"TikTok Help Center","value":"Explains that TikTok Studio includes post analytics such as views, likes, shares, and other performance metrics."},{"href":"https://ads.tiktok.com/help/article/basic-data?lang=en","label":"TikTok Business Help Center","value":"Describes profile visits, clicks, conversions, and other campaign metrics used to understand post or ad outcomes."}]},{"slug":"tiktok-engagement-rate-calculator","title":"TikTok Engagement Rate Calculator","url":"https://toolkitshelf.com/tools/tiktok-engagement-rate-calculator","category":"Social Media Tools","formulaId":"toolkitshelf.formula.tiktok-engagement-rate-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Followers","Views","Likes","Comments","Shares","Saves"],"resultLabel":"Engagement rate","formula":{"expression":"Engagement rate = (likes + comments + shares + saves) / followers x 100","label":"TikTok engagement rate formula","note":"For a single video, divide by views instead of followers to measure engagement per view."},"example":[{"label":"Followers","value":"50,000"},{"label":"Likes + comments + shares + saves","value":"10,010"},{"label":"Engagement rate","value":"20.02%"}],"sources":[{"href":"https://support.tiktok.com/en/using-tiktok/creating-videos/tiktok-studio/","label":"TikTok Help Center","value":"Explains that TikTok Studio includes post analytics such as views, likes, shares, and other performance metrics."}]},{"slug":"brand-deal-calculator","title":"Brand Deal Calculator","url":"https://toolkitshelf.com/tools/brand-deal-calculator","category":"Social Media Tools","formulaId":"toolkitshelf.formula.brand-deal-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Followers","Engagement rate","Deliverables","Production cost","Usage","Exclusivity"],"resultLabel":"Suggested quote","formula":{"expression":"Quote = base audience fee + engagement premium + production cost + usage fee + exclusivity fee","label":"Brand deal pricing formula","note":"The result is an estimate. Final creator rates can change based on niche, content quality, conversion history, and brand demand."},"example":[{"label":"Platform","value":"TikTok"},{"label":"Followers","value":"100,000"},{"label":"Engagement rate","value":"4.2%"},{"label":"Estimated quote","value":"$8,210"}],"sources":[{"href":"https://www.ftc.gov/business-guidance/resources/disclosures-101-social-media-influencers","label":"Federal Trade Commission","value":"Publishes disclosure guidance for social media influencers and endorsements."},{"href":"https://support.google.com/youtube/answer/154235?hl=en","label":"YouTube Help","value":"Explains paid product placements, sponsorships, endorsements, and the need to check local legal resources."}]},{"slug":"brand-deal-profitability-calculator","title":"Brand Deal Profitability Calculator","url":"https://toolkitshelf.com/tools/brand-deal-profitability-calculator","category":"Social Media Tools","formulaId":"toolkitshelf.formula.brand-deal-profitability-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Gross brand fee","Production spend","Contractor cost","Revision buffer","Usage or exclusivity cost","Tax reserve"],"resultLabel":"Estimated take-home","formula":{"expression":"Take-home = gross fee - production costs - contractor costs - revision buffer - usage or exclusivity opportunity cost - payment fees - tax reserve","label":"Brand deal profit formula","note":"The result is a creator business planning estimate. Contract scope, taxes, payment timing, revisions, usage rights, exclusivity, and refunds can change real take-home income."},"example":[{"label":"Gross brand fee","value":"$5,000"},{"label":"Scope costs and payment fee","value":"$2,300"},{"label":"Estimated take-home","value":"$2,025"}],"sources":[{"href":"https://www.ftc.gov/business-guidance/resources/disclosures-101-social-media-influencers","label":"Federal Trade Commission","value":"Publishes disclosure guidance for social media influencers and endorsements."},{"href":"https://support.google.com/youtube/answer/154235?hl=en","label":"YouTube Help","value":"Explains paid product placements, sponsorships, endorsements, and the need to check local legal resources."}]},{"slug":"creator-campaign-breakeven-calculator","title":"Creator Campaign Breakeven Calculator","url":"https://toolkitshelf.com/tools/creator-campaign-breakeven-calculator","category":"Social Media Tools","formulaId":"toolkitshelf.formula.creator-campaign-breakeven-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Creator fee","Production cost","Paid boost","Tools or reporting cost","Expected impressions","Click-through rate","Conversion rate","Average order value","Gross margin"],"resultLabel":"Break-even orders","formula":{"expression":"Break-even orders = total campaign cost / (average order value x gross margin)","label":"Creator campaign breakeven formula","note":"This is a pre-launch planning estimate. Attribution, refunds, discounts, fulfillment cost, and lifetime value can change the real campaign economics."},"example":[{"label":"Total campaign cost","value":"$5,750"},{"label":"Average order value x gross margin","value":"$39.60 gross profit per order"},{"label":"Break-even orders","value":"146 orders"}],"sources":[]},{"slug":"youtube-shorts-rpm-calculator","title":"YouTube Shorts RPM Calculator","url":"https://toolkitshelf.com/tools/youtube-shorts-rpm-calculator","category":"Social Media Tools","formulaId":"toolkitshelf.formula.youtube-shorts-rpm-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Monthly views","RPM","Eligible view share","Monthly uploads"],"resultLabel":"Estimated Shorts revenue","formula":{"expression":"Estimated revenue = monthly views x eligible view share / 1,000 x RPM","label":"Shorts RPM formula","note":"RPM is an assumption you enter. Actual YouTube Shorts revenue can vary by geography, music usage, monetization eligibility, ad market, and policy changes."},"example":[{"label":"Monthly views","value":"1,000,000"},{"label":"RPM","value":"$0.08"},{"label":"Eligible view share","value":"85%"},{"label":"Estimated revenue","value":"$68"}],"sources":[]},{"slug":"youtube-engagement-rate-calculator","title":"YouTube Engagement Rate Calculator","url":"https://toolkitshelf.com/tools/youtube-engagement-rate-calculator","category":"Social Media Tools","formulaId":"toolkitshelf.formula.youtube-engagement-rate-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Views","Subscribers","Likes","Comments","Shares"],"resultLabel":"YouTube engagement rate","formula":{"expression":"Engagement rate = (likes + comments + shares) / views x 100","label":"YouTube engagement formula","note":"Use views for a specific video. Use subscribers when comparing an account against other creator accounts."},"example":[{"label":"Views","value":"86,000"},{"label":"Interactions","value":"3,780"},{"label":"Engagement by views","value":"4.40%"}],"sources":[]},{"slug":"instagram-engagement-rate-calculator","title":"Instagram Engagement Rate Calculator","url":"https://toolkitshelf.com/tools/instagram-engagement-rate-calculator","category":"Social Media Tools","formulaId":"toolkitshelf.formula.instagram-engagement-rate-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Followers","Reach","Likes","Comments","Shares","Saves"],"resultLabel":"Instagram engagement rate","formula":{"expression":"Engagement rate = (likes + comments + shares + saves) / reach x 100","label":"Instagram engagement formula","note":"Use reach for a specific post or reel. Use followers for account-level comparison."},"example":[{"label":"Reach","value":"18,500"},{"label":"Interactions","value":"1,884"},{"label":"Engagement by reach","value":"10.18%"}],"sources":[]},{"slug":"instagram-story-engagement-calculator","title":"Instagram Story Engagement Calculator","url":"https://toolkitshelf.com/tools/instagram-story-engagement-calculator","category":"Social Media Tools","formulaId":"toolkitshelf.formula.instagram-story-engagement-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Story views","Replies","Sticker taps","Taps forward","Taps back","Exits"],"resultLabel":"Instagram Story engagement","formula":{"expression":"Reply rate = replies / story views x 100; exit rate = exits / story views x 100","label":"Story engagement formulas","note":"Compare stories with similar format and length. A single frame and a multi-frame sequence can produce very different navigation behavior."},"example":[{"label":"Story views","value":"12,400"},{"label":"Replies","value":"86"},{"label":"Reply rate","value":"0.69%"}],"sources":[]},{"slug":"sponsorship-cpm-calculator","title":"Sponsorship CPM Calculator","url":"https://toolkitshelf.com/tools/sponsorship-cpm-calculator","category":"Social Media Tools","formulaId":"toolkitshelf.formula.sponsorship-cpm-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Quote","Expected impressions","Deliverables","Production cost"],"resultLabel":"Effective CPM","formula":{"expression":"CPM = sponsorship quote / expected impressions x 1,000","label":"Sponsorship CPM formula","note":"CPM compares price against expected impressions. It does not capture conversion quality, usage rights, exclusivity, or creative value."},"example":[{"label":"Quote","value":"$2,500"},{"label":"Expected impressions","value":"120,000"},{"label":"Effective CPM","value":"$20.83"}],"sources":[]},{"slug":"creator-sponsorship-readiness-calculator","title":"Creator Sponsorship Readiness Calculator","url":"https://toolkitshelf.com/tools/creator-sponsorship-readiness-calculator","category":"Social Media Tools","formulaId":"toolkitshelf.formula.creator-sponsorship-readiness-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Followers","Average views","Engagement rate","Save and share rate","Posts per month","Audience fit score","Conversion proof score","Brand safety score"],"resultLabel":"Sponsorship readiness score","formula":{"expression":"Readiness score = weighted reach + engagement + intent + consistency + audience fit + conversion proof + brand safety","label":"Sponsorship readiness formula","note":"The score is a planning heuristic. It does not replace sponsor requirements, campaign briefs, disclosure rules, or performance history."},"example":[{"label":"Followers","value":"58,000"},{"label":"Average views","value":"42,000"},{"label":"Engagement rate","value":"5.6%"},{"label":"Readiness","value":"Nearly ready"}],"sources":[{"href":"https://www.ftc.gov/business-guidance/resources/disclosures-101-social-media-influencers","label":"Federal Trade Commission","value":"Publishes disclosure guidance for social media influencers and sponsored endorsements."},{"href":"https://support.google.com/youtube/answer/154235?hl=en","label":"YouTube Help","value":"Explains disclosure settings for paid product placements, sponsorships, and endorsements on YouTube."}]},{"slug":"creator-revenue-health-analyzer","title":"Creator Revenue Health Analyzer","url":"https://toolkitshelf.com/tools/creator-revenue-health-analyzer","category":"Social Media Tools","formulaId":"toolkitshelf.formula.creator-revenue-health-analyzer","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Platform revenue","Sponsorship revenue","Affiliate revenue","Product revenue","Services revenue","Monthly costs","Tax reserve"],"resultLabel":"Creator revenue health","formula":{"expression":"Take-home estimate = gross revenue - monthly costs - tax reserve; top stream share = largest revenue stream / gross revenue x 100","label":"Creator revenue health formulas","note":"The diversification score is a planning heuristic based on how evenly revenue is spread across five creator revenue streams."},"example":[{"label":"Gross monthly revenue","value":"$6,540"},{"label":"Largest stream","value":"Sponsors at about 49%"},{"label":"Estimated take-home","value":"$4,262"}],"sources":[{"href":"https://www.ftc.gov/business-guidance/resources/disclosures-101-social-media-influencers","label":"Federal Trade Commission","value":"Publishes disclosure guidance for social media influencers and sponsored endorsements."},{"href":"https://www.irs.gov/businesses/small-businesses-self-employed/self-employed-individuals-tax-center","label":"Internal Revenue Service","value":"Provides self-employment tax guidance for people who work for themselves."}]},{"slug":"creator-income-calculator","title":"Creator Income Calculator","url":"https://toolkitshelf.com/tools/creator-income-calculator","category":"Social Media Tools","formulaId":"toolkitshelf.formula.creator-income-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Platform revenue","Sponsorship revenue","Affiliate revenue","Product revenue","Monthly costs","Tax reserve"],"resultLabel":"Creator take-home estimate","formula":{"expression":"Estimated take-home = revenue streams - monthly costs - tax reserve","label":"Creator income formula","note":"This is a planning estimate, not tax, accounting, or legal advice. Actual take-home depends on entity setup, location, expenses, and tax treatment."},"example":[{"label":"Gross monthly income","value":"$6,040"},{"label":"Monthly costs","value":"$620"},{"label":"Estimated take-home","value":"$3,902"}],"sources":[]},{"slug":"affiliate-commission-calculator","title":"Affiliate Commission Calculator","url":"https://toolkitshelf.com/tools/affiliate-commission-calculator","category":"Social Media Tools","formulaId":"toolkitshelf.formula.affiliate-commission-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Affiliate clicks","Conversion rate","Average order value","Commission rate","Refund rate"],"resultLabel":"Affiliate commission estimate","formula":{"expression":"Net commission = clicks x conversion rate x average order value x commission rate x (1 - refund rate)","label":"Affiliate commission formula","note":"Use confirmed program terms for attribution windows, cookie rules, excluded products, and refund adjustments."},"example":[{"label":"Clicks","value":"4,200"},{"label":"Conversion rate","value":"2.8%"},{"label":"Net commission","value":"$1,114"}],"sources":[]},{"slug":"content-campaign-roi-calculator","title":"Content Campaign ROI Calculator","url":"https://toolkitshelf.com/tools/content-campaign-roi-calculator","category":"Social Media Tools","formulaId":"toolkitshelf.formula.content-campaign-roi-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Production cost","Creator fees","Ad spend","Revenue attributed","Leads or signups"],"resultLabel":"Content campaign ROI","formula":{"expression":"ROI = (revenue attributed - total campaign cost) / total campaign cost x 100","label":"Campaign ROI formula","note":"Attribution can be imperfect. Use consistent attribution windows and include production, creator, media, and tool costs where possible."},"example":[{"label":"Total campaign cost","value":"$5,500"},{"label":"Revenue attributed","value":"$9,600"},{"label":"Campaign ROI","value":"74.5%"}],"sources":[]},{"slug":"tiktok-view-velocity-calculator","title":"TikTok View Velocity Calculator","url":"https://toolkitshelf.com/tools/tiktok-view-velocity-calculator","category":"Social Media Tools","formulaId":"toolkitshelf.formula.tiktok-view-velocity-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Current views","Hours since posted","Engagement rate"],"resultLabel":"Views per hour","formula":{"expression":"Views per hour = current views / hours since posted","label":"View velocity formula","note":"The projections are simple linear pace estimates, not platform predictions."},"example":[{"label":"Current views","value":"84,000"},{"label":"Hours live","value":"18"},{"label":"Views per hour","value":"4,667"}],"sources":[]},{"slug":"tiktok-save-rate-calculator","title":"TikTok Save Rate Calculator","url":"https://toolkitshelf.com/tools/tiktok-save-rate-calculator","category":"Social Media Tools","formulaId":"toolkitshelf.formula.tiktok-save-rate-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Views","Saves","Shares","Likes"],"resultLabel":"Save rate","formula":{"expression":"Save rate = saves / views x 100","label":"TikTok save rate formula","note":"Save rate is a deeper intent metric than likes for many educational, shopping, recipe, and reference posts."},"example":[{"label":"Views","value":"120,000"},{"label":"Saves","value":"980"},{"label":"Save rate","value":"0.82%"}],"sources":[]},{"slug":"google-adsense-calculator","title":"Google AdSense Calculator","url":"https://toolkitshelf.com/tools/google-adsense-calculator","category":"Business Tools","formulaId":"toolkitshelf.formula.google-adsense-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Monthly page views","Page RPM","Ad CTR","Estimated CPC","Eligible traffic share"],"resultLabel":"Estimated AdSense revenue","formula":{"expression":"RPM estimate = eligible page views x page RPM / 1000; CPC estimate = eligible page views x CTR x CPC","label":"AdSense revenue formulas","note":"Use RPM and CPC as separate planning models unless you are reconciling them against actual platform reports."},"example":[{"label":"Monthly page views","value":"50,000"},{"label":"Page RPM","value":"$6.00"},{"label":"Eligible traffic","value":"92%"},{"label":"RPM estimate","value":"$276/month"}],"sources":[{"href":"https://support.google.com/adsense/answer/112030?hl=en","label":"Google AdSense Help","value":"Defines page RPM as estimated earnings divided by page views, multiplied by 1000."}]},{"slug":"cpc-and-cpm-calculator","title":"CPC and CPM Calculator","url":"https://toolkitshelf.com/tools/cpc-and-cpm-calculator","category":"Business Tools","formulaId":"toolkitshelf.formula.cpc-and-cpm-calculator","isCallableViaMcp":true,"lastReviewed":"2026-06-06","mcpTool":"calculate_cpc_and_cpm","inputs":["Ad spend","Impressions","Clicks","Target CPC","Target CPM"],"resultLabel":"CPC, CPM, and CTR","formula":{"expression":"CPC = ad spend / clicks; CPM = ad spend / impressions x 1000; CTR = clicks / impressions x 100","label":"CPC and CPM formulas","note":"Use the same reporting window, currency, click definition, and impression source for every input."},"example":[{"label":"Ad spend","value":"$24,000"},{"label":"Impressions","value":"8,000,000"},{"label":"Clicks","value":"12,000"},{"label":"Result","value":"$2.00 CPC, $3.00 CPM, 0.15% CTR"}],"sources":[{"href":"https://support.google.com/google-ads/answer/14074?hl=en","label":"Google Ads Help","value":"Defines average CPC and how click costs are calculated in Google Ads reporting."}]},{"slug":"cpa-calculator-cost-per-acquisition","title":"CPA Calculator - Cost per Acquisition","url":"https://toolkitshelf.com/tools/cpa-calculator-cost-per-acquisition","category":"Business Tools","formulaId":"toolkitshelf.formula.cpa-calculator-cost-per-acquisition","isCallableViaMcp":true,"lastReviewed":"2026-06-06","mcpTool":"calculate_cpa","inputs":["Campaign spend","Acquisitions","Target CPA","Average order value","Gross margin"],"resultLabel":"CPA and target spend gap","formula":{"expression":"CPA = campaign spend / acquisitions; target spend = target CPA x acquisitions","label":"CPA formula","note":"Define acquisition consistently and keep the attribution window, currency, channel filter, and conversion source aligned."},"example":[{"label":"Campaign spend","value":"$24,000"},{"label":"Acquisitions","value":"480"},{"label":"CPA","value":"$50.00"},{"label":"Gross profit after CPA","value":"$76.00 per acquisition"}],"sources":[{"href":"https://support.google.com/google-ads/answer/6268632?hl=en","label":"Google Ads Help","value":"Explains target CPA bidding and the cost-per-action objective in Google Ads."}]},{"slug":"consulting-fees-calculator","title":"Consulting Fees Calculator","url":"https://toolkitshelf.com/tools/consulting-fees-calculator","category":"Business Tools","formulaId":"toolkitshelf.formula.consulting-fees-calculator","isCallableViaMcp":true,"lastReviewed":"2026-06-06","mcpTool":"calculate_consulting_fees","inputs":["Billable hours","Hourly rate","Direct expenses","Overhead","Scope buffer","Discount"],"resultLabel":"Consulting fee and effective hourly rate","formula":{"expression":"Consulting fee = labor fee + overhead + scope buffer + direct expenses - discount","label":"Consulting fee formula","note":"Use scoped hours and a blended hourly rate for the same project, then keep overhead, buffer, expenses, and discounts separate."},"example":[{"label":"Billable hours","value":"80"},{"label":"Hourly rate","value":"$150.00"},{"label":"Consulting fee","value":"$15,561.00"},{"label":"Effective hourly rate","value":"$194.51"}],"sources":[{"href":"https://www.sba.gov/business-guide/plan-your-business/calculate-your-startup-costs","label":"U.S. Small Business Administration","value":"Discusses pricing products and services by understanding costs, customers, and competition."}]},{"slug":"lerner-index-calculator","title":"Lerner Index Calculator","url":"https://toolkitshelf.com/tools/lerner-index-calculator","category":"Business Tools","formulaId":"toolkitshelf.formula.lerner-index-calculator","isCallableViaMcp":true,"lastReviewed":"2026-06-06","mcpTool":"calculate_lerner_index","inputs":["Price per unit","Marginal cost","Target index","Demand risk"],"resultLabel":"Lerner Index and pricing power","formula":{"expression":"Lerner Index = (price - marginal cost) / price","label":"Lerner Index formula","note":"Use the same unit, currency, product mix, and time window for price and marginal cost before comparing results."},"example":[{"label":"Price","value":"$40.00"},{"label":"Marginal cost","value":"$30.00"},{"label":"Lerner Index","value":"0.250"},{"label":"Pricing power","value":"Moderate pricing power"}],"sources":[{"href":"https://frds.io/measures/lerner_index/","label":"Financial Research Data Services","value":"Defines the Lerner Index as the price-cost markup divided by price for pricing-power analysis."}]},{"slug":"grp-calculator","title":"GRP Calculator","url":"https://toolkitshelf.com/tools/grp-calculator","category":"Business Tools","formulaId":"toolkitshelf.formula.grp-calculator","isCallableViaMcp":true,"lastReviewed":"2026-06-06","mcpTool":"calculate_grp","inputs":["Reach","Average frequency","Target audience","Media spend","Target GRP"],"resultLabel":"GRP, cost per point, and target gap","formula":{"expression":"GRP = reach (%) x average frequency","label":"GRP formula","note":"Use reach and average frequency from the same target audience, channel scope, and campaign window."},"example":[{"label":"Reach","value":"45.0%"},{"label":"Average frequency","value":"2.80"},{"label":"GRP","value":"126.0"},{"label":"Cost per point","value":"$476.19"}],"sources":[{"href":"https://marketing-dictionary.org/g/gross-rating-point/","label":"Universal Marketing Dictionary","value":"Defines gross rating point and gives the GRP formula as reach percentage multiplied by average frequency."},{"href":"https://support.google.com/google-ads/answer/2472714?hl=en","label":"Google Ads Help","value":"Documents reach and frequency metrics for understanding how many people saw ads and how often."}]},{"slug":"conversion-rate-calculator","title":"Conversion Rate Calculator","url":"https://toolkitshelf.com/tools/conversion-rate-calculator","category":"Business Tools","formulaId":"toolkitshelf.formula.conversion-rate-calculator","isCallableViaMcp":true,"lastReviewed":"2026-06-06","mcpTool":"calculate_conversion_rate","inputs":["Conversions","Visitors or clicks","Target rate","Baseline rate"],"resultLabel":"Conversion rate and target gap","formula":{"expression":"Conversion rate = conversions / selected denominator x 100; target conversions = denominator x target rate / 100","label":"Conversion rate formula","note":"Use the same conversion event, denominator, tracking window, and filtering rules before comparing rates."},"example":[{"label":"Conversions","value":"480"},{"label":"Visitors or clicks","value":"12,000"},{"label":"Conversion rate","value":"4.00%"},{"label":"Target","value":"600 conversions needed for a 5.00% rate"}],"sources":[{"href":"https://support.google.com/analytics/answer/9267735?hl=en","label":"Google Analytics Help","value":"Documents key event rates and conversion-style reporting concepts for web and app analytics."},{"href":"https://support.google.com/google-ads/answer/2684489?hl=en","label":"Google Ads Help","value":"Defines conversion rate as conversions divided by eligible interactions."}]},{"slug":"ctr-calculator","title":"CTR Calculator","url":"https://toolkitshelf.com/tools/ctr-calculator","category":"Business Tools","formulaId":"toolkitshelf.formula.ctr-calculator","isCallableViaMcp":true,"lastReviewed":"2026-06-06","mcpTool":"calculate_ctr","inputs":["Clicks","Impressions","Target CTR","Baseline CTR"],"resultLabel":"Click-through rate and target gap","formula":{"expression":"CTR = clicks / impressions x 100; target clicks = impressions x target CTR / 100","label":"CTR formula","note":"Use the same impression source, click filters, placement, channel, and reporting window before comparing CTR."},"example":[{"label":"Clicks","value":"120,000"},{"label":"Impressions","value":"4,000,000"},{"label":"CTR","value":"3.00%"},{"label":"Target","value":"140,000 clicks needed for a 3.50% CTR"}],"sources":[{"href":"https://support.google.com/google-ads/answer/2615875?hl=en","label":"Google Ads Help","value":"Defines click-through rate as clicks divided by impressions for ads and listings."},{"href":"https://support.google.com/webmasters/answer/7042828?hl=en","label":"Google Search Console Help","value":"Defines CTR for Search Console as clicks divided by impressions."}]},{"slug":"average-collection-period-calculator","title":"Average Collection Period Calculator","url":"https://toolkitshelf.com/tools/average-collection-period-calculator","category":"Business Tools","formulaId":"toolkitshelf.formula.average-collection-period-calculator","isCallableViaMcp":true,"lastReviewed":"2026-06-06","mcpTool":"calculate_average_collection_period","inputs":["Beginning accounts receivable","Ending accounts receivable","Net credit sales","Days in period","Credit terms"],"resultLabel":"Collection period and terms gap","formula":{"expression":"Average collection period = average accounts receivable / net credit sales x days in period","label":"Average collection period formula","note":"Use net credit sales and accounts receivable from the same reporting period; cash sales and mismatched dates can distort the result."},"example":[{"label":"Beginning AR","value":"$100,000"},{"label":"Ending AR","value":"$140,000"},{"label":"Net credit sales","value":"$1,000,000"},{"label":"Average collection period","value":"43.8 days"}],"sources":[{"href":"https://www.accountingtools.com/articles/average-collection-period.html","label":"AccountingTools","value":"Defines average collection period and gives the average receivables divided by daily annual sales formula."}]},{"slug":"additional-funds-needed-calculator","title":"Additional Funds Needed Calculator","url":"https://toolkitshelf.com/tools/additional-funds-needed-calculator","category":"Business Tools","formulaId":"toolkitshelf.formula.additional-funds-needed-calculator","isCallableViaMcp":true,"lastReviewed":"2026-06-06","mcpTool":"calculate_additional_funds_needed","inputs":["Current sales","Projected sales","Sales-linked assets","Spontaneous liabilities","Net profit margin","Retention ratio"],"resultLabel":"External financing gap","formula":{"expression":"AFN = (sales-linked assets / current sales x sales increase) - (spontaneous liabilities / current sales x sales increase) - (projected sales x net profit margin x retention ratio)","label":"Additional funds needed formula","note":"Use operating assets and spontaneous liabilities that genuinely scale with sales; deliberate financing decisions belong after the gap is estimated."},"example":[{"label":"Current sales","value":"$900,000"},{"label":"Projected sales","value":"$1,200,000"},{"label":"Required asset increase","value":"$180,000"},{"label":"Additional funds needed","value":"$48,000"}],"sources":[{"href":"https://biz.libretexts.org/Bookshelves/Finance/Introduction_to_Financial_Analysis_%28Bigel%29/02%3A_Part_II-_Ratio_Analysis_and_Forecasting_Modeling/09%3A_Corporate_Forecasting_Models/9.04%3A_External_Funds_Needed_Formula%28EFN%29","label":"LibreTexts Business","value":"Open textbook explanation of EFN/AFN as required asset growth less spontaneous liabilities and retained earnings."},{"href":"https://www.sba.gov/business-guide/plan-your-business/fund-your-business","label":"U.S. Small Business Administration","value":"Small-business funding guidance for comparing funding sources after estimating how much capital is needed."}]},{"slug":"accumulated-depreciation-calculator","title":"Accumulated Depreciation Calculator","url":"https://toolkitshelf.com/tools/accumulated-depreciation-calculator","category":"Business Tools","formulaId":"toolkitshelf.formula.accumulated-depreciation-calculator","isCallableViaMcp":true,"lastReviewed":"2026-06-06","mcpTool":"calculate_accumulated_depreciation","inputs":["Asset cost","Salvage value","Useful life","Completed years","Depreciation method"],"resultLabel":"Accumulated depreciation and book value","formula":{"expression":"Straight-line accumulated depreciation = ((asset cost - salvage value) / useful life) x completed years; book value = asset cost - accumulated depreciation","label":"Accumulated depreciation formula","note":"This is a planning estimate for book schedules. Tax depreciation, partial-year conventions, impairments, and disposal accounting may require separate treatment."},"example":[{"label":"Asset cost","value":"$50,000"},{"label":"Salvage value","value":"$5,000"},{"label":"Completed years","value":"3 of 5"},{"label":"Accumulated depreciation","value":"$27,000"}],"sources":[{"href":"https://www.accountingtools.com/articles/what-is-accumulated-depreciation.html","label":"AccountingTools","value":"Defines accumulated depreciation as total depreciation charged since an asset was acquired and available for use."},{"href":"https://www.xero.com/guides/what-is-accumulated-depreciation/","label":"Xero","value":"Explains straight-line depreciation as asset cost less salvage value divided by useful life."}]},{"slug":"burndown-chart-calculator","title":"Burndown Chart Calculator","url":"https://toolkitshelf.com/tools/burndown-chart-calculator","category":"Business Tools","formulaId":"toolkitshelf.formula.burndown-chart-calculator","isCallableViaMcp":true,"lastReviewed":"2026-06-06","mcpTool":"calculate_burndown_chart","inputs":["Planned work","Scope added","Completed work","Sprint days","Days elapsed"],"resultLabel":"Sprint burndown status","formula":{"expression":"Remaining work = adjusted scope - completed work; ideal remaining = adjusted scope x (1 - days elapsed / sprint days)","label":"Burndown chart formula","note":"Use one consistent work unit such as story points, hours, tasks, or tickets. Scope changes should be tracked separately from completed work."},"example":[{"label":"Planned work","value":"200 points"},{"label":"Scope added","value":"20 points"},{"label":"Completed work","value":"120 points by day 6"},{"label":"Status","value":"At risk; projected finish day 11.0"}],"sources":[{"href":"https://www.atlassian.com/agile/tutorials/burndown-charts","label":"Atlassian Agile","value":"Explains burndown charts as remaining work over time with an ideal effort line for sprint tracking."},{"href":"https://www.scrum.org/resources/forecasting-techniques","label":"Scrum.org","value":"Describes burndown as a way to create transparency on progress by showing work still remaining over time."}]},{"slug":"evm-calculator","title":"EVM Calculator","url":"https://toolkitshelf.com/tools/evm-calculator","category":"Business Tools","formulaId":"toolkitshelf.formula.evm-calculator","isCallableViaMcp":true,"lastReviewed":"2026-06-06","mcpTool":"calculate_evm","inputs":["Earned value","Planned value","Actual cost","Budget at completion"],"resultLabel":"Earned value project health","formula":{"expression":"CV = EV - AC; SV = EV - PV; CPI = EV / AC; SPI = EV / PV; EAC = BAC / CPI","label":"EVM formula","note":"Use one scope baseline, progress rule, currency, and reporting date before comparing EV, PV, AC, and BAC."},"example":[{"label":"Earned value","value":"$420,000"},{"label":"Planned value","value":"$460,000"},{"label":"Actual cost","value":"$460,000"},{"label":"Status","value":"Cost and schedule risk"}],"sources":[{"href":"https://www.energy.gov/documents/evmmodule6pdf","label":"U.S. Department of Energy","value":"Earned value guidance covers common EV, PV, AC, cost variance, schedule variance, CPI, and SPI terminology."}]},{"slug":"direct-material-price-variance-calculator","title":"Direct Material Price Variance Calculator","url":"https://toolkitshelf.com/tools/direct-material-price-variance-calculator","category":"Business Tools","formulaId":"toolkitshelf.formula.direct-material-price-variance-calculator","isCallableViaMcp":true,"lastReviewed":"2026-06-06","mcpTool":"calculate_direct_material_price_variance","inputs":["Actual quantity","Standard quantity","Actual unit price","Standard unit price"],"resultLabel":"Direct material price variance","formula":{"expression":"Direct material price variance = (actual unit price - standard unit price) x actual quantity","label":"Direct material price variance formula","note":"Use the same unit of measure, material grade, purchase basis, and reporting period before interpreting favorable or unfavorable variance."},"example":[{"label":"Actual quantity","value":"1,000 units"},{"label":"Actual unit price","value":"$12.00"},{"label":"Standard unit price","value":"$10.00"},{"label":"Price variance","value":"$2,000 unfavorable"}],"sources":[{"href":"https://www.accountingtools.com/articles/what-is-the-direct-material-price-variance.html","label":"AccountingTools","value":"Defines direct material price variance as actual price less budgeted price, multiplied by actual quantity acquired."},{"href":"https://openstax.org/books/principles-managerial-accounting/pages/8-2-compute-and-evaluate-materials-variances","label":"OpenStax Managerial Accounting","value":"Explains direct material variances and the relationship between actual quantity, actual price, standard quantity, and standard price."}]},{"slug":"fifo-calculator-for-inventory","title":"FIFO Calculator for Inventory","url":"https://toolkitshelf.com/tools/fifo-calculator-for-inventory","category":"Business Tools","formulaId":"toolkitshelf.formula.fifo-calculator-for-inventory","isCallableViaMcp":true,"lastReviewed":"2026-06-06","mcpTool":"calculate_fifo_inventory","inputs":["Beginning units","Beginning unit cost","Purchase units","Purchase unit cost","Units sold","Selling price"],"resultLabel":"FIFO COGS and ending inventory","formula":{"expression":"FIFO COGS = oldest units sold x oldest unit cost, then next-oldest units x next unit cost; ending inventory = remaining units x their layer costs","label":"FIFO inventory formula","note":"FIFO assumes the earliest acquired inventory costs flow to COGS first, leaving newer costs in ending inventory."},"example":[{"label":"Beginning layer","value":"120 units @ $8.00"},{"label":"Purchase layer","value":"200 units @ $11.00"},{"label":"Units sold","value":"180"},{"label":"FIFO output","value":"$1,620 COGS; $1,540 ending inventory"}],"sources":[{"href":"https://openstax.org/books/principles-financial-accounting/pages/10-2-calculate-the-cost-of-goods-sold-and-ending-inventory-using-the-periodic-method","label":"OpenStax Financial Accounting","value":"Explains FIFO as earliest purchased units sold first, with newer costs remaining in ending inventory."}]},{"slug":"hhi-calculator-herfindahl-hirschman-index-calculator","title":"HHI Calculator","url":"https://toolkitshelf.com/tools/hhi-calculator-herfindahl-hirschman-index-calculator","category":"Business Tools","formulaId":"toolkitshelf.formula.hhi-calculator-herfindahl-hirschman-index-calculator","isCallableViaMcp":true,"lastReviewed":"2026-06-06","mcpTool":"calculate_hhi","inputs":["Market shares","Merging share A","Merging share B"],"resultLabel":"HHI and merger concentration screen","formula":{"expression":"HHI = share1^2 + share2^2 + ... + sharen^2; merger delta HHI = 2 x share A x share B","label":"HHI formula","note":"Use market shares from the same relevant market, geography, product scope, and reporting period before comparing HHI values."},"example":[{"label":"Market shares","value":"35%, 25%, 20%, 20%"},{"label":"Pre-merger HHI","value":"2,650"},{"label":"Merger delta","value":"1,750"},{"label":"Post-merger HHI","value":"4,400"}],"sources":[{"href":"https://www.justice.gov/atr/herfindahl-hirschman-index","label":"U.S. Department of Justice","value":"Defines HHI as the sum of squared market shares and lists DOJ/FTC concentration bands."},{"href":"https://www.justice.gov/atr/merger-guidelines/applying-merger-guidelines/guideline-1","label":"2023 Merger Guidelines","value":"States that HHI above 1,800 is highly concentrated and a change above 100 points is significant."}]},{"slug":"labor-cost-calculator","title":"Labor Cost Calculator","url":"https://toolkitshelf.com/tools/labor-cost-calculator","category":"Business Tools","formulaId":"toolkitshelf.formula.labor-cost-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Regular hours","Overtime hours","Base hourly rate","Overtime multiplier","Benefits and payroll load","Extra employer costs"],"resultLabel":"Loaded labor cost","formula":{"expression":"Loaded labor cost = (regular hours x hourly rate + overtime hours x hourly rate x overtime multiplier) x (1 + payroll load) + extra employer costs","label":"Labor cost formula","note":"Payroll load can include benefits, legally required costs, insurance, retirement, and other employer-paid compensation costs."},"example":[{"label":"Regular hours","value":"160"},{"label":"Overtime hours","value":"8"},{"label":"Base rate","value":"$32/hour"},{"label":"Loaded cost","value":"About $7,600"}],"sources":[{"href":"https://www.bls.gov/ecec/","label":"U.S. Bureau of Labor Statistics","value":"ECEC measures employer costs per hour worked for wages, salaries, benefits, and total compensation."}]},{"slug":"liquid-net-worth-calculator","title":"Liquid Net Worth Calculator","url":"https://toolkitshelf.com/tools/liquid-net-worth-calculator","category":"Money Calculators","formulaId":"toolkitshelf.formula.liquid-net-worth-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Cash and equivalents","Taxable liquid investments","Other liquid assets","Liquidity haircut","Current liabilities","Monthly spending"],"resultLabel":"Liquid net worth","formula":{"expression":"Liquid net worth = cash and equivalents + liquid assets after haircut - current liabilities","label":"Liquid net worth formula","note":"A haircut reduces marketable or near-cash assets for taxes, fees, volatility, or conversion risk."},"example":[{"label":"Cash and equivalents","value":"$24,000"},{"label":"Liquid investments","value":"$32,000 with 10% haircut"},{"label":"Current liabilities","value":"$12,500"},{"label":"Liquid net worth","value":"$40,300"}],"sources":[{"href":"https://www.nerdwallet.com/article/finance/liquid-net-worth","label":"NerdWallet","value":"Describes liquid net worth as cash and assets quickly convertible to cash, minus debts."}]},{"slug":"payback-period-calculator","title":"Payback Period Calculator","url":"https://toolkitshelf.com/tools/payback-period-calculator","category":"Business Tools","formulaId":"toolkitshelf.formula.payback-period-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Initial investment","Implementation cost","Annual net cash inflow","Residual value"],"resultLabel":"Payback period","formula":{"expression":"Payback period = net investment to recover / annual net cash inflow","label":"Payback period formula","note":"For uneven cash flows, calculate cumulative recovery period by period instead of relying only on the straight-line estimate."},"example":[{"label":"Initial investment","value":"$120,000"},{"label":"Implementation cost","value":"$15,000"},{"label":"Annual net inflow","value":"$42,000"},{"label":"Payback period","value":"About 3.0 years"}],"sources":[{"href":"https://openstax.org/books/principles-finance/pages/16-1-payback-period-method","label":"OpenStax Principles of Finance","value":"Explains the payback period method for capital budgeting."}]},{"slug":"profitability-index-calculator","title":"Profitability Index Calculator","url":"https://toolkitshelf.com/tools/profitability-index-calculator","category":"Business Tools","formulaId":"toolkitshelf.formula.profitability-index-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Initial investment","Annual cash flow","Project horizon","Discount rate","Terminal value"],"resultLabel":"Profitability index","formula":{"expression":"Profitability index = present value of future cash flows / initial investment","label":"Profitability index formula","note":"A result above 1.0 means modeled discounted benefits exceed the initial investment before other constraints are considered."},"example":[{"label":"Initial investment","value":"$120,000"},{"label":"Annual cash flow","value":"$42,000 for 4 years"},{"label":"Discount rate","value":"10%"},{"label":"Profitability index","value":"1.11"}],"sources":[{"href":"https://openstax.org/books/principles-finance/pages/16-4-alternative-methods","label":"OpenStax Principles of Finance","value":"Covers profitability index as a capital budgeting alternative using discounted cash flow inputs."}]},{"slug":"drive-time-calculator","title":"Drive Time Calculator","url":"https://toolkitshelf.com/tools/drive-time-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.drive-time-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Distance","Average speed","Stop time","Delay buffer"],"resultLabel":"Estimated drive time","formula":{"expression":"Total drive time = distance / average speed + stop time + delay buffer","label":"Drive time formula","note":"Distance and speed must use matching units, such as miles and miles per hour."},"example":[{"label":"Distance","value":"120 miles"},{"label":"Average speed","value":"60 mph"},{"label":"Stops and delay","value":"30 minutes"},{"label":"Total drive time","value":"2 hr 30 min"}],"sources":[{"href":"https://openstax.org/books/physics/pages/2-2-speed-and-velocity","label":"OpenStax Physics","value":"Defines average speed as distance traveled divided by elapsed time."}]},{"slug":"miles-per-year-calculator","title":"Miles Per Year Calculator","url":"https://toolkitshelf.com/tools/miles-per-year-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.miles-per-year-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Miles per driving day","Driving days per week","Active weeks per year","Extra trip miles","Service interval"],"resultLabel":"Annual mileage","formula":{"expression":"Annual miles = miles per driving day x driving days per week x active weeks per year + extra trip miles","label":"Annual mileage formula","note":"Use active weeks to avoid overstating mileage during vacation or seasonal downtime."},"example":[{"label":"Miles per day","value":"38"},{"label":"Driving days/week","value":"5"},{"label":"Active weeks/year","value":"46"},{"label":"Annual miles","value":"8,740 plus extra trips"}],"sources":[{"href":"https://www.fhwa.dot.gov/policyinformation/statistics/2024/vm1.cfm","label":"Federal Highway Administration","value":"Publishes annual vehicle distance traveled and related mileage data in Highway Statistics."}]},{"slug":"tesla-charging-cost-calculator","title":"EV Charging Cost Calculator for Tesla and Other EVs","url":"https://toolkitshelf.com/tools/tesla-charging-cost-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.tesla-charging-cost-calculator","isCallableViaMcp":false,"lastReviewed":"2026-07-13","inputs":["Miles driven","kWh per 100 miles","Electricity price","Charging loss","Charges per month"],"resultLabel":"Estimated charging cost","formula":{"expression":"Charging cost = miles x kWh per 100 miles / 100 x electricity price / (1 - charging loss)","label":"EV charging cost formula","note":"Use your actual vehicle efficiency and electricity rate for a useful estimate."},"example":[{"label":"Miles driven","value":"220"},{"label":"Efficiency","value":"30 kWh/100 mi"},{"label":"Electricity rate","value":"$0.28/kWh"},{"label":"Trip cost","value":"About $20.53 with 10% losses"}],"sources":[{"href":"https://afdc.energy.gov/fuels/electricity-charging-home","label":"Alternative Fuels Data Center","value":"Explains how electricity price and vehicle efficiency in kilowatt-hours per distance determine home charging cost."},{"href":"https://www.nist.gov/pml/owm/electric-vehicle-fueling-faqs","label":"NIST","value":"Notes that retail electricity sold as vehicle fuel is measured in kilowatt-hours."}],"provenance":{"calculationClass":"estimate","intendedAudience":"Tesla and other EV drivers comparing trip or monthly charging-cost scenarios from vehicle efficiency, electricity price, and charging loss.","maintainedBy":"Toolkit Shelf","materiallyReviewedAt":"2026-07-13","methodVersion":"toolkitshelf.ev-charging-energy-cost.v1","primarySource":{"href":"https://afdc.energy.gov/fuels/electricity-charging-home","label":"U.S. Department of Energy Alternative Fuels Data Center","sourceDate":"Accessed July 13, 2026"},"relianceBoundary":"This is an energy-cost estimate, not a charger quote, utility bill, vehicle range prediction, charging-speed forecast, or brand-specific charging recommendation.","sourceCheckedAt":"2026-07-13","sourceFreshness":"The general relationship between vehicle energy use and electricity price was checked on July 13, 2026. No live tariff, vehicle telemetry, or brand-specific rate is embedded.","validityConditions":"Use the actual EV's kWh per 100 miles, the applicable home or public charging price, and a reasonable charging-loss estimate. Weather, driving conditions, fees, idle charges, and time-varying tariffs can change actual cost."}},{"slug":"carpooling-calculator","title":"Carpooling Calculator","url":"https://toolkitshelf.com/tools/carpooling-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.carpooling-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["One-way commute distance","Commute days per month","Fuel economy","Fuel price","Riders sharing cost"],"resultLabel":"Monthly carpool savings","formula":{"expression":"Solo monthly fuel cost = round-trip miles x commute days / MPG x fuel price; shared cost per person = solo cost / riders","label":"Carpool fuel cost formula","note":"This estimates fuel only. Add parking, tolls, time, and route detours separately if they matter."},"example":[{"label":"One-way distance","value":"18 miles"},{"label":"Commute days/month","value":"20"},{"label":"Fuel economy","value":"28 mpg"},{"label":"Per-person savings","value":"About $61/month with 3 riders"}],"sources":[{"href":"https://afdc.energy.gov/conserve/ridesharing","label":"Alternative Fuels Data Center","value":"The U.S. DOE AFDC describes ridesharing as a way to reduce travel costs, traffic, and parking demand."}]},{"slug":"engine-hours-to-miles-converter","title":"Engine Hours to Miles Converter","url":"https://toolkitshelf.com/tools/engine-hours-to-miles-converter","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.engine-hours-to-miles-converter","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Engine hours","Effective average speed","Idle share","Duty-cycle adjustment"],"resultLabel":"Estimated miles","formula":{"expression":"Estimated miles = engine hours x effective average speed x (1 - idle share) x duty-cycle adjustment","label":"Engine hours to miles formula","note":"This is a planning conversion. Use actual odometer or telematics data when available."},"example":[{"label":"Engine hours","value":"150"},{"label":"Effective speed","value":"45 mph"},{"label":"Idle share","value":"10%"},{"label":"Estimated miles","value":"6,075 miles"}],"sources":[{"href":"https://openstax.org/books/physics/pages/2-2-speed-and-velocity","label":"OpenStax Physics","value":"Defines average speed as distance traveled divided by elapsed time."}]},{"slug":"boat-speed-calculator","title":"Boat Speed Calculator","url":"https://toolkitshelf.com/tools/boat-speed-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.boat-speed-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Distance in nautical miles","Elapsed time","Current adjustment"],"resultLabel":"Boat speed","formula":{"expression":"Speed over ground = nautical miles / elapsed hours; current-adjusted speed = speed over ground - signed current","label":"Boat speed formula","note":"Enter helping current as positive and opposing current as negative if you want a still-water estimate."},"example":[{"label":"Distance","value":"5.2 nautical miles"},{"label":"Elapsed time","value":"40 minutes"},{"label":"Speed over ground","value":"7.8 knots"},{"label":"With helping current","value":"6.6 knots still-water estimate"}],"sources":[{"href":"https://openstax.org/books/physics/pages/2-2-speed-and-velocity","label":"OpenStax Physics","value":"Defines average speed as distance traveled divided by elapsed time."},{"href":"https://www.nist.gov/pml/special-publication-811/nist-guide-si-appendix-b-conversion-factors/nist-guide-si-appendix-b8","label":"NIST SI Guide","value":"Lists the nautical mile conversion factor as 1852 meters."}]},{"slug":"nautical-mile-calculator","title":"Nautical Mile Calculator","url":"https://toolkitshelf.com/tools/nautical-mile-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.nautical-mile-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Nautical miles"],"resultLabel":"Converted distance","formula":{"expression":"1 nautical mile = 1852 meters = 1.852 kilometers = about 1.15078 statute miles","label":"Nautical mile conversion","note":"Keep more precision internally if the conversion feeds another route or speed calculation."},"example":[{"label":"Input","value":"10 nautical miles"},{"label":"Statute miles","value":"11.51 mi"},{"label":"Kilometers","value":"18.52 km"}],"sources":[{"href":"https://www.nist.gov/pml/special-publication-811/nist-guide-si-appendix-b-conversion-factors/nist-guide-si-appendix-b8","label":"NIST SI Guide","value":"Lists the nautical mile conversion factor as 1852 meters."}]},{"slug":"tire-size-calculator","title":"Tire Size Calculator","url":"https://toolkitshelf.com/tools/tire-size-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.tire-size-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Section width","Aspect ratio","Wheel diameter","Original tire diameter"],"resultLabel":"Tire diameter","formula":{"expression":"Sidewall height = section width x aspect ratio / 100; overall diameter = wheel diameter + 2 x sidewall height","label":"Tire diameter formula","note":"Convert sidewall height from millimeters to inches before adding it to wheel diameter in inches."},"example":[{"label":"Tire size","value":"225/55R17"},{"label":"Sidewall height","value":"123.8 mm"},{"label":"Overall diameter","value":"26.7 in"},{"label":"Revs per mile","value":"About 756"}],"sources":[{"href":"https://www.nhtsa.gov/sites/nhtsa.gov/files/brochure.pdf","label":"NHTSA","value":"Explains tire size markings including nominal width, aspect ratio, and rim diameter."}]},{"slug":"traffic-density-calculator","title":"Traffic Density Calculator","url":"https://toolkitshelf.com/tools/traffic-density-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.traffic-density-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Vehicle count","Road length","Lane count","Average speed"],"resultLabel":"Traffic density","formula":{"expression":"Traffic density = vehicles / road length; per-lane density = vehicles / (road length x lane count)","label":"Traffic density formula","note":"Use a consistent observation segment and time window before comparing density between scenarios."},"example":[{"label":"Vehicle count","value":"180"},{"label":"Road length","value":"2 miles"},{"label":"Lane count","value":"3"},{"label":"Density","value":"30 vehicles/lane-mile"}],"sources":[{"href":"https://ops.fhwa.dot.gov/publications/fhwahop08024/fhwa_hop_08_024.pdf","label":"Federal Highway Administration","value":"Traffic engineering materials define density in vehicles per mile or vehicles per mile per lane."}]},{"slug":"acreage-calculator","title":"Acreage Calculator","url":"https://toolkitshelf.com/tools/acreage-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.acreage-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Length","Width","Input unit","Usable area share"],"resultLabel":"Acres","formula":{"expression":"Acres = length x width x unit factor squared x usable share / 43,560","label":"Acreage formula","note":"Convert both dimensions to feet first when using the 43,560 square feet per acre relationship."},"example":[{"label":"Length","value":"250 ft"},{"label":"Width","value":"180 ft"},{"label":"Area","value":"45,000 sq ft"},{"label":"Acreage","value":"About 1.033 acres"}],"sources":[{"href":"https://www.nist.gov/pml/special-publication-811/nist-guide-si-appendix-b-conversion-factors/nist-guide-si-appendix-b8","label":"NIST SI Guide","value":"Lists official conversion factors for acre, are, and metric area units."}]},{"slug":"area-converter","title":"Area Converter","url":"https://toolkitshelf.com/tools/area-converter","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.area-converter","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Area value","From unit","To unit"],"resultLabel":"Converted area","formula":{"expression":"Converted area = input area x from-unit square-meter factor / to-unit square-meter factor","label":"Area conversion formula","note":"Area factors are squared length relationships, so changing length units is not enough by itself."},"example":[{"label":"Input","value":"1 acre"},{"label":"Square feet","value":"43,560 sq ft"},{"label":"Square meters","value":"About 4,046.86 sq m"}],"sources":[{"href":"https://www.nist.gov/pml/special-publication-811/nist-guide-si-appendix-b-conversion-factors/nist-guide-si-appendix-b8","label":"NIST SI Guide","value":"Lists conversion factors for acre, are, square foot, and other area-related units."}]},{"slug":"length-converter","title":"Length Converter","url":"https://toolkitshelf.com/tools/length-converter","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.length-converter","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Length value","From unit","To unit"],"resultLabel":"Converted length","formula":{"expression":"Converted length = input length x from-unit meter factor / to-unit meter factor","label":"Length conversion formula","note":"The converter uses meters as the shared base for length units."},"example":[{"label":"Input","value":"12 ft"},{"label":"Meters","value":"3.6576 m"},{"label":"Inches","value":"144 in"}],"sources":[{"href":"https://www.nist.gov/pml/special-publication-811/nist-guide-si-appendix-b-conversion-factors/nist-guide-si-appendix-b8","label":"NIST SI Guide","value":"Lists conversion factors for inch, foot, yard, mile, meter, and related units."}]},{"slug":"feet-to-inches-calculator","title":"Feet to Inches Calculator","url":"https://toolkitshelf.com/tools/feet-to-inches-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.feet-to-inches-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Feet","Extra inches"],"resultLabel":"Total inches","formula":{"expression":"Total inches = feet x 12 + extra inches","label":"Feet to inches formula","note":"Use the extra inches field for mixed measurements such as 5 ft 8 in."},"example":[{"label":"Input","value":"5 ft 8 in"},{"label":"Total inches","value":"68 in"},{"label":"Centimeters","value":"172.72 cm"}],"sources":[{"href":"https://www.nist.gov/pml/special-publication-811/nist-guide-si-appendix-b-conversion-factors/nist-guide-si-appendix-b8","label":"NIST SI Guide","value":"Lists conversion factors for inch and foot length units."}]},{"slug":"cubic-feet-calculator","title":"Cubic Feet Calculator","url":"https://toolkitshelf.com/tools/cubic-feet-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.cubic-feet-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Length","Width","Height","Input unit"],"resultLabel":"Cubic feet","formula":{"expression":"Cubic feet = length in feet x width in feet x height in feet","label":"Cubic feet formula","note":"Convert every dimension to feet before multiplying when the input is inches, yards, or meters."},"example":[{"label":"Dimensions","value":"8 ft x 6 ft x 4 ft"},{"label":"Cubic feet","value":"192 ft³"},{"label":"Cubic yards","value":"7.11 yd³"}],"sources":[{"href":"https://www.nist.gov/pml/special-publication-811/nist-guide-si-appendix-b-conversion-factors/nist-guide-si-appendix-b8","label":"NIST SI Guide","value":"Lists conversion factors for foot, yard, meter, and cubic-volume units."}]},{"slug":"grams-to-ounces-calculator","title":"Grams to Ounces Calculator","url":"https://toolkitshelf.com/tools/grams-to-ounces-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.grams-to-ounces-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Grams","Ounce type"],"resultLabel":"Ounces","formula":{"expression":"Ounces = grams / grams per selected ounce","label":"Grams to ounces formula","note":"Use avoirdupois ounces for ordinary weight and troy ounces only when the source context uses troy weight."},"example":[{"label":"Input","value":"250 g"},{"label":"Avoirdupois ounces","value":"8.82 oz"},{"label":"Pounds","value":"0.551 lb"}],"sources":[{"href":"https://www.nist.gov/pml/special-publication-811/nist-guide-si-appendix-b-conversion-factors/nist-guide-si-appendix-b8","label":"NIST SI Guide","value":"Lists conversion factors for avoirdupois and troy ounces to grams."}]},{"slug":"commute-calculator","title":"Commute Calculator","url":"https://toolkitshelf.com/tools/commute-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.commute-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["One-way distance","Average speed","Buffer each way","Workdays per week"],"resultLabel":"Commute time","formula":{"expression":"One-way moving time = distance / average speed; daily time = one-way time x 2 + buffer each way x 2","label":"Commute time formula","note":"Average speed should reflect real traffic, stops, and route conditions rather than the posted speed limit."},"example":[{"label":"One-way distance","value":"18 mi"},{"label":"Average speed","value":"32 mph"},{"label":"Buffer each way","value":"8 min"},{"label":"Daily time","value":"About 1 hr 24 min"}],"sources":[{"href":"https://openstax.org/books/physics/pages/2-2-speed-and-velocity","label":"OpenStax Physics","value":"Defines average speed as distance traveled divided by elapsed time."}]},{"slug":"speed-calculator","title":"Speed Calculator","url":"https://toolkitshelf.com/tools/speed-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.speed-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Distance","Distance unit","Hours","Minutes"],"resultLabel":"Speed","formula":{"expression":"Speed = distance / elapsed time","label":"Speed formula","note":"Use the same distance and time interval for the whole calculation. Stops and delays should be included if you want average trip speed."},"example":[{"label":"Distance","value":"120 mi"},{"label":"Elapsed time","value":"2 hr 15 min"},{"label":"Speed","value":"53.33 mph"}],"sources":[{"href":"https://openstax.org/books/physics/pages/2-2-speed-and-velocity","label":"OpenStax Physics","value":"Defines average speed as distance traveled divided by elapsed time."},{"href":"https://www.nist.gov/pml/special-publication-811/nist-guide-si-appendix-b-conversion-factors/nist-guide-si-appendix-b8","label":"NIST SI Guide","value":"Lists conversion factors for mile, kilometer, and nautical mile units."}]},{"slug":"pixels-to-inches-converter","title":"Pixels to Inches Converter","url":"https://toolkitshelf.com/tools/pixels-to-inches-converter","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.pixels-to-inches-converter","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Pixels","PPI or DPI"],"resultLabel":"Inches","formula":{"expression":"Inches = pixels / pixels per inch","label":"Pixels to inches formula","note":"Pixel count alone does not define physical size; the PPI or DPI assumption is required."},"example":[{"label":"Pixels","value":"1920 px"},{"label":"PPI","value":"300"},{"label":"Physical length","value":"6.4 in"}],"sources":[{"href":"https://www.nist.gov/pml/special-publication-811/nist-guide-si-appendix-b-conversion-factors/nist-guide-si-appendix-b8","label":"NIST SI Guide","value":"Lists the exact inch-to-meter relationship used for metric dimension output."}]},{"slug":"cubic-meter-calculator","title":"Cubic Meter Calculator","url":"https://toolkitshelf.com/tools/cubic-meter-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.cubic-meter-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Length","Width","Height","Input unit"],"resultLabel":"Cubic meters","formula":{"expression":"Cubic meters = length in meters x width in meters x height in meters","label":"Cubic meter formula","note":"Convert every dimension to meters before multiplying when inputs are feet, inches, yards, or centimeters."},"example":[{"label":"Dimensions","value":"2.4 m x 1.8 m x 1.2 m"},{"label":"Cubic meters","value":"5.184 m³"},{"label":"Liters","value":"5,184 L"}],"sources":[{"href":"https://www.nist.gov/pml/special-publication-811/nist-guide-si-appendix-b-conversion-factors/nist-guide-si-appendix-b8","label":"NIST SI Guide","value":"Lists conversion factors for foot, yard, meter, liter, and cubic-volume units."}]},{"slug":"ares-to-hectares-converter","title":"Ares to Hectares Converter","url":"https://toolkitshelf.com/tools/ares-to-hectares-converter","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.ares-to-hectares-converter","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Ares"],"resultLabel":"Hectares","formula":{"expression":"Hectares = ares / 100","label":"Ares to hectares formula","note":"One are is 100 square meters, and one hectare is 100 ares."},"example":[{"label":"Input","value":"250 ares"},{"label":"Hectares","value":"2.5 ha"},{"label":"Square meters","value":"25,000 m²"}],"sources":[{"href":"https://www.nist.gov/pml/special-publication-811/nist-guide-si-appendix-b-conversion-factors/nist-guide-si-appendix-b8","label":"NIST SI Guide","value":"Lists conversion factors for are, hectare, acre, and square-meter area units."}]},{"slug":"inches-to-fraction-calculator","title":"Inches to Fraction Calculator","url":"https://toolkitshelf.com/tools/inches-to-fraction-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.inches-to-fraction-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Decimal inches","Nearest fraction"],"resultLabel":"Fractional inches","formula":{"expression":"Fraction numerator = round(decimal remainder x denominator); reduce numerator and denominator by their greatest common divisor","label":"Decimal inches to fraction formula","note":"Choose a denominator that matches the precision of the measuring tool or material tolerance."},"example":[{"label":"Decimal inches","value":"2.375 in"},{"label":"Nearest 1/16","value":"2 3/8 in"},{"label":"Metric","value":"60.33 mm"}],"sources":[{"href":"https://www.nist.gov/pml/special-publication-811/nist-guide-si-appendix-b-conversion-factors/nist-guide-si-appendix-b8","label":"NIST SI Guide","value":"Lists the exact inch-to-meter relationship used for metric output."}]},{"slug":"decimeter-to-meter-converter","title":"Decimeter to Meter Converter","url":"https://toolkitshelf.com/tools/decimeter-to-meter-converter","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.decimeter-to-meter-converter","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Decimeters"],"resultLabel":"Meters","formula":{"expression":"Meters = decimeters / 10","label":"Decimeters to meters formula","note":"The deci prefix means one tenth, so one decimeter is one tenth of a meter."},"example":[{"label":"Input","value":"35 dm"},{"label":"Meters","value":"3.5 m"},{"label":"Centimeters","value":"350 cm"}],"sources":[{"href":"https://www.nist.gov/pml/owm/metric-si-prefixes","label":"NIST Metric SI Prefixes","value":"Documents metric prefix relationships, including deci as one tenth of the base unit."}]},{"slug":"decagram-to-gram-converter","title":"Decagram to Gram Converter","url":"https://toolkitshelf.com/tools/decagram-to-gram-converter","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.decagram-to-gram-converter","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Decagrams"],"resultLabel":"Grams","formula":{"expression":"Grams = decagrams x 10","label":"Decagrams to grams formula","note":"The deka/deca prefix means ten, so one decagram is ten grams."},"example":[{"label":"Input","value":"12 dag"},{"label":"Grams","value":"120 g"},{"label":"Kilograms","value":"0.12 kg"}],"sources":[{"href":"https://www.nist.gov/pml/owm/metric-si-prefixes","label":"NIST Metric SI Prefixes","value":"Documents metric prefix relationships, including deka as ten times the base unit."},{"href":"https://www.nist.gov/pml/special-publication-811/nist-guide-si-appendix-b-conversion-factors/nist-guide-si-appendix-b8","label":"NIST SI Guide","value":"Lists the pound-to-kilogram relationship used for customary mass comparison."}]},{"slug":"gallon-calculator","title":"Gallon Calculator","url":"https://toolkitshelf.com/tools/gallon-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.gallon-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Volume","From unit","To unit"],"resultLabel":"Converted volume","formula":{"expression":"Converted volume = input volume x from-unit liter factor / to-unit liter factor","label":"Gallon conversion formula","note":"Choose U.S. gallon or imperial gallon deliberately because they are different volumes."},"example":[{"label":"Input","value":"2.5 U.S. gal"},{"label":"Quarts","value":"10 qt"},{"label":"Liters","value":"9.46 L"}],"sources":[{"href":"https://www.nist.gov/pml/special-publication-811/nist-guide-si-appendix-b-conversion-factors/nist-guide-si-appendix-b8","label":"NIST SI Guide","value":"Lists conversion factors for U.S. gallons, imperial gallons, liters, and cubic-volume units."}]},{"slug":"cubic-yards-to-tons-calculator","title":"Cubic Yards to Tons Calculator","url":"https://toolkitshelf.com/tools/cubic-yards-to-tons-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.cubic-yards-to-tons-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Cubic yards","Density","Adjustment factor"],"resultLabel":"Estimated short tons","formula":{"expression":"Short tons = cubic yards x tons per cubic yard x adjustment factor","label":"Cubic yards to tons formula","note":"Density varies by material, moisture, and compaction, so use supplier values for final orders."},"example":[{"label":"Cubic yards","value":"5 yd³"},{"label":"Density","value":"1.35 short tons/yd³"},{"label":"Estimated weight","value":"6.75 short tons"}],"sources":[{"href":"https://www.nist.gov/pml/special-publication-811/nist-guide-si-appendix-b-conversion-factors/nist-guide-si-appendix-b8","label":"NIST SI Guide","value":"Lists conversion factors for cubic yards and short tons."},{"href":"https://www.nist.gov/system/files/documents/2024/01/14/NIST%20HB%2044%202024%20Appendix%20C%20General%20Tables%20of%20Units%20of%20Measurement.pdf","label":"NIST Handbook 44 Appendix C","value":"Lists the U.S. short ton as 2,000 pounds."}]},{"slug":"gallons-to-pounds-converter","title":"Gallons to Pounds Converter","url":"https://toolkitshelf.com/tools/gallons-to-pounds-converter","category":"Everyday 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units."},{"href":"https://www.nist.gov/system/files/documents/2024/01/14/NIST%20HB%2044%202024%20Appendix%20C%20General%20Tables%20of%20Units%20of%20Measurement.pdf","label":"NIST Handbook 44 Appendix C","value":"Lists the U.S. short ton as 2,000 pounds for mass comparisons."}]},{"slug":"astronomical-unit-calculator","title":"Astronomical Unit Calculator","url":"https://toolkitshelf.com/tools/astronomical-unit-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.astronomical-unit-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Distance","From unit","To unit"],"resultLabel":"Converted astronomy distance","formula":{"expression":"1 AU = 149,597,870,700 meters exactly","label":"Astronomical unit formula","note":"The calculator uses the IAU fixed astronomical unit and then applies standard length conversions."},"example":[{"label":"Input","value":"1 AU"},{"label":"Kilometers","value":"149,597,870.7 km"},{"label":"Miles","value":"About 92,955,807.3 mi"}],"sources":[{"href":"https://www.iau.org/IAU/Iau/Publications/List-of-Resolutions.aspx","label":"International Astronomical Union","value":"Defines the astronomical unit as exactly 149,597,870,700 meters."},{"href":"https://www.nist.gov/physical-measurement-laboratory/nist-guide-si-appendix-b8","label":"NIST SI Guide","value":"Lists standard length conversion factors used for meter, kilometer, mile, and related units."}]},{"slug":"mesh-to-micron-converter","title":"Mesh to Micron Converter","url":"https://toolkitshelf.com/tools/mesh-to-micron-converter","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.mesh-to-micron-converter","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Mesh number"],"resultLabel":"Estimated microns","formula":{"expression":"Micron opening = standard sieve aperture lookup for the selected mesh number","label":"Mesh to micron lookup","note":"Mesh number is not a universal formula; wire diameter and sieve standard affect the actual opening."},"example":[{"label":"Mesh","value":"100"},{"label":"Opening","value":"About 150 microns"},{"label":"Millimeters","value":"0.150 mm"}],"sources":[{"href":"https://store.astm.org/e0011-15.html","label":"ASTM E11","value":"Describes woven-wire test sieve requirements and nominal aperture sizes for test sieves."},{"href":"https://nvlpubs.nist.gov/nistpubs/Legacy/TN/nbstechnicalnote1096.pdf","label":"NIST Technical Note 1096","value":"Includes mesh-size and particle-diameter relationships for standard sieve series."}]},{"slug":"miles-to-dollars-calculator","title":"Miles to Dollars Calculator","url":"https://toolkitshelf.com/tools/miles-to-dollars-calculator","category":"Everyday Calculators","formulaId":"toolkitshelf.formula.miles-to-dollars-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Miles","Cost per mile","Trip count","Fixed charges"],"resultLabel":"Estimated dollars","formula":{"expression":"Total cost = miles x cost per mile x trip count + fixed charges","label":"Miles to dollars formula","note":"Keep the cost-per-mile basis consistent: fuel-only, reimbursement, or all-in operating cost."},"example":[{"label":"Miles","value":"500"},{"label":"Cost per mile","value":"$0.725"},{"label":"Fixed charges","value":"$25"},{"label":"Total cost","value":"$387.50"}],"sources":[{"href":"https://www.irs.gov/newsroom/irs-sets-2026-business-standard-mileage-rate-at-725-cents-per-mile-up-25-cents","label":"IRS 2026 Standard Mileage Rate","value":"Announces the 2026 optional business standard mileage rate of 72.5 cents per mile."},{"href":"https://www.irs.gov/tax-professionals/standard-mileage-rates","label":"IRS Standard Mileage Rates","value":"Lists mileage-rate history and explains when standard mileage rates may apply."}]},{"slug":"oz-to-cups-converter","title":"Ounces to Cups Converter","url":"https://toolkitshelf.com/tools/oz-to-cups-converter","category":"Everyday 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Weight ounces require ingredient density and should not use this direct cup conversion."},"example":[{"label":"Fluid ounces","value":"16 fl oz"},{"label":"U.S. cups","value":"2 cups"},{"label":"Milliliters","value":"473.18 mL"}],"sources":[{"href":"https://www.nist.gov/physical-measurement-laboratory/nist-guide-si-appendix-b8","label":"NIST SI Guide","value":"Lists U.S. fluid ounce and volume conversion factors used for milliliter output."},{"href":"https://www.nist.gov/pml/owm/metric-household","label":"NIST Metric Household","value":"Provides household volume equivalents for cups, fluid ounces, teaspoons, and tablespoons."}]},{"slug":"decision-matrix-calculator","title":"Decision Matrix Calculator","url":"https://toolkitshelf.com/tools/decision-matrix-calculator","category":"Business Tools","formulaId":"toolkitshelf.formula.decision-matrix-calculator","isCallableViaMcp":true,"lastReviewed":"2026-06-06","mcpTool":"calculate_decision_matrix","inputs":["Impact weight","Confidence weight","Effort weight","Risk weight","Option scores"],"resultLabel":"Ranked decision score","formula":{"expression":"Score = weighted average of impact, confidence, low effort, and low risk","label":"Decision matrix score formula","note":"Effort and risk are inverted because lower effort and lower risk improve the weighted score."},"example":[{"label":"Top option","value":"Option A"},{"label":"Weighted score","value":"About 77 / 100"},{"label":"Main tradeoff","value":"High impact with moderate effort"}],"sources":[]},{"slug":"prioritization-score-calculator","title":"Prioritization Score Calculator","url":"https://toolkitshelf.com/tools/prioritization-score-calculator","category":"Business Tools","formulaId":"toolkitshelf.formula.prioritization-score-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Scoring method","Reach","Impact","Confidence","Effort","Ease","Option scores"],"resultLabel":"Ranked prioritization score","formula":{"expression":"RICE = reach x impact x confidence / effort; ICE = impact x confidence x ease","label":"Prioritization score formula","note":"RICE is useful when reach and effort estimates are available. ICE is faster when the comparison is still rough."},"example":[{"label":"Top priority","value":"Option A"},{"label":"RICE score","value":"About 480 in the sample case"},{"label":"ICE score","value":"Normalized to a 0-100 scale"}],"sources":[]},{"slug":"meeting-cost-calculator","title":"Meeting Cost Calculator","url":"https://toolkitshelf.com/tools/meeting-cost-calculator","category":"Business Tools","formulaId":"toolkitshelf.formula.meeting-cost-calculator","isCallableViaMcp":true,"lastReviewed":"2026-06-06","mcpTool":"calculate_meeting_cost","inputs":["Attendees","Meeting minutes","Prep or follow-up minutes","Loaded hourly cost","Meetings per week","Weeks per year"],"resultLabel":"Meeting cost","formula":{"expression":"Cost per meeting = attendees x (meeting minutes + prep minutes) / 60 x loaded hourly cost","label":"Meeting cost formula","note":"Recurring cost multiplies the per-meeting cost by meetings per week and active weeks per year."},"example":[{"label":"Attendees","value":"8 people"},{"label":"Meeting length","value":"45 minutes plus 10 minutes prep/follow-up"},{"label":"Annual cost","value":"About $57k at 2 meetings/week and $85/hour"}],"sources":[]},{"slug":"policy-exception-cost-calculator","title":"Policy Exception Cost Calculator","url":"https://toolkitshelf.com/tools/policy-exception-cost-calculator","category":"Business Tools","formulaId":"toolkitshelf.formula.policy-exception-cost-calculator","isCallableViaMcp":false,"lastReviewed":"2026-06-06","inputs":["Exceptions per month","Minutes per exception","Reviewer loaded hourly cost","Escalation rate","Escalation minutes","Escalation hourly cost","Rework or error rate","Cost per rework","Approval meetings","Risk buffer"],"resultLabel":"Monthly exception cost","formula":{"expression":"Monthly cost = review labor + escalation labor + rework cost + approval meeting cost + risk buffer","label":"Policy exception cost formula","note":"The risk buffer is applied after direct review, escalation, rework, and approval meeting costs."},"example":[{"label":"Exceptions","value":"120 per month"},{"label":"Review labor","value":"24 hours/month at 12 minutes each"},{"label":"Monthly cost","value":"About $7k with escalation, rework, meetings, and buffer"}],"sources":[]},{"slug":"kpi-guardrail-checker","title":"KPI Guardrail Checker","url":"https://toolkitshelf.com/tools/kpi-guardrail-checker","category":"Business Tools","formulaId":"toolkitshelf.formula.kpi-guardrail-checker","isCallableViaMcp":true,"lastReviewed":"2026-06-06","mcpTool":"calculate_kpi_guardrail","inputs":["Primary KPI direction","Baseline KPI value","Current KPI value","Warning threshold","Rollback threshold","Error rate thresholds","Support ticket thresholds","Measurement window"],"resultLabel":"Guardrail status","formula":{"expression":"Status = worst threshold state across primary KPI, error rate, and support tickets","label":"KPI guardrail formula","note":"Higher-is-better KPIs trigger watch or rollback when the current value falls below thresholds. Lower-is-better metrics trigger when the current value rises above thresholds."},"example":[{"label":"Primary KPI","value":"96 against a 90 rollback threshold"},{"label":"Error rate","value":"2.2% against a 4.0% rollback threshold"},{"label":"Status","value":"Continue in the sample case"}],"sources":[]},{"slug":"pricing-change-impact-calculator","title":"Pricing Change Impact Calculator","url":"https://toolkitshelf.com/tools/pricing-change-impact-calculator","category":"Business Tools","formulaId":"toolkitshelf.formula.pricing-change-impact-calculator","isCallableViaMcp":true,"lastReviewed":"2026-06-06","mcpTool":"calculate_pricing_change_impact","inputs":["Current price","Proposed price","Current units per month","Expected volume change","Variable cost per unit","Fixed cost per month"],"resultLabel":"Pricing impact","formula":{"expression":"Projected profit = projected units x (proposed price - variable cost) - fixed cost","label":"Pricing change impact formula","note":"Projected units use the expected volume change. Break-even volume shows how many units are needed at the proposed price to preserve current gross profit."},"example":[{"label":"Current price","value":"$49"},{"label":"Proposed price","value":"$59 with 8% expected volume loss"},{"label":"Result","value":"Revenue and profit improve in the sample case"}],"sources":[]},{"slug":"build-vs-buy-calculator","title":"Build vs Buy Calculator","url":"https://toolkitshelf.com/tools/build-vs-buy-calculator","category":"Business Tools","formulaId":"toolkitshelf.formula.build-vs-buy-calculator","isCallableViaMcp":true,"lastReviewed":"2026-06-06","mcpTool":"calculate_build_vs_buy","inputs":["Build hours","Loaded hourly cost","Maintenance hours","Risk buffer","Vendor setup cost","Vendor monthly cost","Comparison months"],"resultLabel":"Lower cost option","formula":{"expression":"Build total = build labor x risk buffer + maintenance cost; buy total = setup cost + monthly vendor cost","label":"Build vs buy formula","note":"The comparison is a cost model only. It does not decide strategy, security, data control, switching cost, or product fit."},"example":[{"label":"Build total","value":"$30,780"},{"label":"Buy total","value":"$16,900"},{"label":"Lower cost option","value":"Buy is cheaper"}],"sources":[]},{"slug":"automation-roi-calculator","title":"Automation ROI Calculator","url":"https://toolkitshelf.com/tools/automation-roi-calculator","category":"Business Tools","formulaId":"toolkitshelf.formula.automation-roi-calculator","isCallableViaMcp":true,"lastReviewed":"2026-06-06","mcpTool":"calculate_automation_roi","inputs":["Manual hours per week","Loaded hourly cost","Error or rework cost","Time saved","Rework reduction","Automation monthly cost","Implementation hours","Setup cost","Maintenance hours"],"resultLabel":"Automation payback","formula":{"expression":"Monthly savings = current monthly cost - automated monthly cost; payback = implementation cost / monthly savings","label":"Automation ROI formula","note":"Current cost includes manual labor and rework. Automated cost includes remaining labor, remaining rework, software, and maintenance."},"example":[{"label":"Current cost","value":"About $7,856/month"},{"label":"Net monthly savings","value":"About $2,393/month"},{"label":"Payback","value":"About 2.5 months in the sample case"}],"sources":[]},{"slug":"vendor-comparison-calculator","title":"Vendor Comparison Calculator","url":"https://toolkitshelf.com/tools/vendor-comparison-calculator","category":"Business Tools","formulaId":"toolkitshelf.formula.vendor-comparison-calculator","isCallableViaMcp":true,"lastReviewed":"2026-06-06","mcpTool":"calculate_vendor_comparison","inputs":["Comparison months","Feature fit weight","Support weight","Integration effort weight","Risk weight","Cost weight","Vendor monthly costs","Vendor setup costs","Vendor fit and risk scores"],"resultLabel":"Ranked vendor score","formula":{"expression":"Score = weighted average of feature fit, support, low integration effort, low risk, and normalized low cost","label":"Vendor comparison score formula","note":"Lower integration effort, lower risk, and lower modeled cost improve the weighted score. Cost is normalized across the vendors entered."},"example":[{"label":"Top vendor","value":"Vendor A"},{"label":"Weighted score","value":"About 78 / 100"},{"label":"Modeled cost","value":"$16,900 over 12 months"}],"sources":[]},{"slug":"manual-review-cost-calculator","title":"Manual Review Cost Calculator","url":"https://toolkitshelf.com/tools/manual-review-cost-calculator","category":"Business Tools","formulaId":"toolkitshelf.formula.manual-review-cost-calculator","isCallableViaMcp":true,"lastReviewed":"2026-06-06","mcpTool":"calculate_manual_review_cost","inputs":["Reviews per day","Minutes per review","Loaded hourly cost","Workdays per month","QA overhead","Automation coverage","Automation monthly cost","Implementation cost"],"resultLabel":"Monthly review cost","formula":{"expression":"Monthly cost = reviews per day x workdays x minutes per review / 60 x hourly cost x overhead","label":"Manual review cost formula","note":"Automation savings subtract the ongoing automation cost from the labor cost covered by the automation assumption."},"example":[{"label":"Monthly reviews","value":"9,900"},{"label":"Current cost","value":"About $15k/month"},{"label":"Payback","value":"Under 1 year in the sample case"}],"sources":[]},{"slug":"password-generator","title":"Secure Password Generator","url":"https://toolkitshelf.com/tools/password-generator","category":"Utility Tools","formulaId":"toolkitshelf.formula.password-generator","isCallableViaMcp":false,"lastReviewed":"2026-07-13","inputs":["Password length","Uppercase option","Lowercase option","Number option","Symbol option","Ambiguous-character option"],"resultLabel":"Random password","formula":{"expression":"Password = Web Crypto random selections from the enabled character sets, including at least one character from every enabled set","label":"Secure random generation method","note":"Selection uses rejection sampling to avoid modulo bias. The displayed entropy is an approximate search-space estimate and is not a security guarantee."},"example":[{"label":"Default length","value":"20 characters"},{"label":"Default sets","value":"Lowercase, uppercase, numbers, and symbols"},{"label":"Processing","value":"In this browser"}],"sources":[{"href":"https://developer.mozilla.org/en-US/docs/Web/API/Crypto/getRandomValues","label":"MDN Web Docs - Crypto.getRandomValues","value":"Documents the browser API used to obtain cryptographically strong random values."},{"href":"https://pages.nist.gov/800-63-4/sp800-63b.html","label":"NIST SP 800-63B","value":"Provides current password and authenticator guidance, including length, blocklists, password managers, and rate limiting."}],"provenance":{"calculationClass":"deterministic","intendedAudience":"People generating a unique random credential locally before storing it in a trusted password manager.","maintainedBy":"Toolkit Shelf","materiallyReviewedAt":"2026-07-13","methodVersion":"toolkitshelf.password-web-crypto.v1","primarySource":{"href":"https://developer.mozilla.org/en-US/docs/Web/API/Crypto/getRandomValues","label":"MDN Crypto.getRandomValues documentation","sourceDate":"Accessed July 13, 2026"},"relianceBoundary":"The generator supplies random text, not account protection, secure storage, breach monitoring, phishing resistance, recovery, multi-factor authentication, or a guarantee that a destination accepts the selected characters.","sourceCheckedAt":"2026-07-13","sourceFreshness":"The browser Web Crypto API and current NIST password guidance were checked on July 13, 2026. No external password database, server request, or live account policy is used.","validityConditions":"Use a browser with crypto.getRandomValues, select at least one character set, confirm the destination's password rules, keep the result unique, and store it securely. The entropy number is an approximate alphabet-size model rather than a security guarantee."}}]}