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Tool directory

Free calculators that show their work

Fast calculators and tools for money, home projects, dates, health, work, shopping, unit conversions, writing, UTM links, QR codes, and everyday math. Each tool keeps the inputs, result, formula or method, assumptions, and limits visible.

Open search for tool name, input, category, or result
All toolsMoney calculators
Popular starting points294 tools live
Percentage CalculatorUse this percentage calculator for common percent math: find a percent of a number, calculate percentage change, or work out what percent one value is of another.Mortgage Affordability CalculatorUse this mortgage affordability calculator to estimate how much house you can afford from income, debts, down payment, rate, loan term, property taxes, insurance, HOA, and debt-limit assumptions.Electricity Bill CalculatorUse this electricity bill calculator to turn monthly kWh and your utility rate into a simple bill estimate.Utility Bill Split CalculatorUse this utility bill split calculator to divide monthly household bills between roommates or household members.Cups to Grams CalculatorUse this cups to grams calculator for common cooking and baking ingredients where ingredient density changes the conversion.Gas Trip Cost CalculatorUse this gas trip cost calculator to estimate gallons, total fuel cost, cost per mile, and cost per person for a drive.Time Card CalculatorUse this time card calculator to turn start time, end time, break minutes, days worked, and hourly rate into daily hours, weekly hours, and gross pay.Square Footage CalculatorUse this square footage calculator to multiply length by width in feet or meters, total multiple spaces, and estimate material cost.Budget CalculatorUse this budget calculator to compare monthly income against housing, food, transportation, debt, savings, and other spending.Rent Split CalculatorUse this rent split calculator to divide rent and utilities equally or by a custom percentage for roommates and shared housing.Credit Card Interest CalculatorUse this credit card interest calculator to estimate billing cycle interest before checking a statement, payoff plan, monthly interest estimate, or debt snowball scenario.
No account requiredFormula shownExamples includedMobile friendly

Browse by category

Find the tool that matches the question.

Categories stay broad, but each tool page is named around the exact task people search for.

Quick daily mathEveryday Calculators

Common calculators for percentages, dates, tips, age, time, unit conversions, home projects, and other everyday questions.

Personal financeMoney Calculators

Simple calculators for budget, tax estimates, emergency funds, debt payoff, loans, savings, rent, salary, mortgage affordability, and household money math.

Body and nutritionHealth Calculators

Quick health and fitness calculators for BMI, calorie estimates, weight ranges, and everyday wellness planning.

Work and pricingBusiness Tools

Practical tools for rates, invoices, cash flow, cash runway, profit, pricing, and small business planning.

Social metricsSocial Media Tools

Creator tools for TikTok, Instagram, YouTube, engagement, save rates, Shorts RPM, sponsorship pricing, media kits, creator income, and campaign ROI.

Words and namesText and Writing Tools

Text tools for word count, characters, case conversion, hashtags, meta descriptions, platform limits, usernames, hooks, headlines, bios, and CTAs.

Files, links, and web tasksUtility Tools

Browser-first utilities for QR codes, links, files, formats, web snippets, and other practical tasks that do not need a spreadsheet-style calculator.

Popular calculator tasks

Start from the decision you are trying to make.

These groups connect common everyday questions to the calculators that answer them directly.

Shop, split, and compare prices

Fast calculators for discounts, sales tax, tips, unit prices, fuel costs, and percentage checks before you buy.

Discount calculatorSale price, savings, and estimated taxUnit price calculatorCompare price per ounce, pound, item, or servingPrice per pound calculatorCompare grocery and bulk packages by cost per poundPrice per ounce calculatorCompare grocery and household packages by cost per ouncePrice per gram calculatorMetric package comparison by gram and per 100g

Measure rooms and home projects

Practical calculators for square footage, paint, tile, concrete, mulch, soil, sod, gravel, fencing, utilities, and appliance energy.

Square footage calculatorRoom area, total area, and material cost estimateHome project cost plannerMaterials, labor, fees, contingency, budget, and cost per square footPaint calculatorWall area, gallons needed, and paint costRoom paint calculatorRoom dimensions, wall count, coats, gallons, and costConcrete calculatorCubic yards, 80 lb bags, and material cost

Convert units and recipe measurements

Specific conversion calculators for common searches: inches, pounds, miles, cups, tablespoons, grams, and kitchen measurements.

Inches to centimeters calculatorExact inch-to-centimeter conversionPounds to kilograms calculatorWeight conversion for body, luggage, shipping, and gym weightsMiles to kilometers calculatorDistance conversion for driving, races, and mapsCups to tablespoons calculatorUS kitchen conversion for recipesCups to grams calculatorIngredient-aware flour, sugar, butter, oats, rice, and liquid conversions

Plan household money decisions

Budget, paycheck, rent, bill splitting, emergency fund, and savings calculators for household planning.

Budget calculatorMonthly income, spending, savings, and surplusSubscription cost calculatorMonthly, annual, and potentially unused recurring spendHousehold supplies budget calculatorPaper, cleaning, laundry, personal care, and other suppliesPaycheck calculatorGross pay, estimated deductions, and take-home payEmergency fund calculatorSavings target and time to reach it

Compare loans and payoff plans

Loan calculators for monthly payments, mortgage planning, refinancing, auto loans, and debt payoff.

Mortgage payment calculatorPrincipal, interest, taxes, insurance, and HOAMortgage vs rent calculatorCompare owner net cost with rent cost over a holding periodCar affordability calculatorVehicle price from monthly budget, APR, tax, and feesLoan comparison calculatorCompare monthly payment, total interest, and total costLoan interest calculatorTotal interest, payoff time, and annual interest preview

Check dates, work hours, and school math

Everyday calculators for date ranges, age, time duration, time cards, grades, GPA, averages, and fractions.

Days between dates calculatorCalendar days, weeks, and optional end-date countingBusiness days calculatorWeekdays between dates after holiday or PTO adjustmentsAdd business days calculatorDeadline date after adding workdays and skipping weekendsCountdown calculatorDays, weeks, and approximate months until a target dateTime duration calculatorElapsed time between two clock times
Browse every task group in the directory

Web page QA workflow

Check the page before you send traffic.

Start with the final URL, then check redirects, headers, indexing signals, previews, schema, headings, image alt text, and links.

Website page QA checklistRedirect Chain CheckerHTTP Headers + Cache CheckerCanonical URL + Meta Robots CheckerRobots.txt + Sitemap CheckerOpen Graph + Twitter Card CheckerJSON-LD Structured Data CheckerHeading Structure + H1 CheckerImage Alt Text CheckerPage Links + Anchor Text Checker

Templates

Copy the setup before calculating.

Template pages give you Markdown, CSV, and checklist formats for workflows that need a little structure before the math.

All templatesDecision Matrix TemplateVendor Comparison TemplateBrand Deal Pricing Template

More useful paths

Go deeper without scanning the whole directory.

The homepage stays curated. Use these paths when you need the full library, a page-check workflow, a decision workflow, or a copyable template.

Full directoryFind the exact tool page

Search and filter every live calculator, checker, generator, converter, and utility by task, input, or category.

Web page QACheck a page before promotion

Use the ordered checklist for redirects, headers, indexability, previews, schema, headings, images, and links.

Work decisionsCompare options with visible assumptions

Start with decision matrix, build-vs-buy, vendor comparison, meeting cost, and manual review cost tools.

TemplatesCopy a reusable setup

Use Markdown, CSV, and checklist formats when a workflow needs structure before the calculator result.

GuidesFollow a workflow instead of one-off math

Read practical guides that connect related tools into shopping, writing, moving, business, and page-QA workflows.

Tool standards

Built for checking the math or method, not reading around it.

Tool pages prioritize the usable tool, formula or method, worked example, benchmarks, limitations, and related tools.

No account required
Formula shown
Examples included
Mobile friendly