Quick answer
Time Duration Calculator: what it calculates
Time Duration Calculator calculates net duration from start time, end time, break minutes, and hourly rate. The visible formula is Net duration = end time - start time - break time.
Everyday Calculators
Time Duration Calculator
Use this time duration calculator to find hours and minutes between two times, subtract breaks, and estimate pay from an hourly rate.
Last reviewed June 6, 2026Source note includedFree tool
Live calculator
Time duration
Net duration8h 0m
8h 30m before breaks.
Decimal hours8
Useful for timesheets, billing, and payroll estimates.
Estimated pay$200.00
Decimal hours multiplied by the hourly rate.
ResultNet duration
InputsStart time, End time, Break minutes, Hourly rate
FormulaTime duration formula
Formula
Time duration formula
Net duration = end time - start time - break timeIf the end time is earlier than the start time, the calculator treats it as ending the next day.
How to use
Steps
- Enter the start time.
- Enter the end time.
- Add unpaid break minutes if needed.
- Use the decimal hours result for billing, payroll, or timesheets.
Example
Sample calculation
Start time9:00 AM
End time5:30 PM
Break30 minutes
Net duration8h 0m
Calculator use
Best for
- Use this time duration calculator to find hours and minutes between two times, subtract breaks, and estimate pay from an hourly rate.
- Checking calendar, work-hour, school, deadline, age, or duration math before copying the result elsewhere.
- Comparing inclusive versus exclusive dates, breaks, grading weights, or time spans with the assumptions visible.
- Doing a quick schedule or school planning check without opening a spreadsheet.
Before relying on it
Check first
- Mixing inclusive and exclusive date counting, time zones, overnight shifts, unpaid breaks, holidays, or school-specific grading rules.
- Rounding time or grades too early and then using the rounded result in another calculation.
- Treating a planning result as payroll, HR, transcript, legal deadline, or official school policy.
Details
What to know before using the result
These notes make the assumptions explicit, especially where the same search query can mean slightly different things.
Overnight shiftsEnd time next day
When the end time is earlier than the start time, the calculator treats the end as occurring after midnight.
Break handlingSubtract unpaid breaks
Enter only the break minutes you want removed from the total. Paid breaks should stay in the worked duration.
Decimal hoursUseful for billing
The decimal-hours result converts minutes into a fraction of an hour for timesheets, invoices, and pay estimates.
Source notes
References used for this calculator
Benchmarks
How to read the result
The calculator is a decision aid, not a fixed rule. Use the output to compare scenarios and document your assumptions. Benchmark ranges are broad planning heuristics unless this page names a specific source for the range.
4 hours: Half shift.
Common for part-time work blocks and appointment windows.
8 hours: Full shift.
A common baseline for workday and timesheet math.
12+ hours: Long day.
Check overtime, break rules, or fatigue-sensitive schedules.
Calculator accuracy
Methodology and assumptions
The formula, inputs, example, and limitations are shown so the result is checkable, not just a number in a box.
Formula
Net duration = end time - start time - break time
Inputs used
Start time, End time, Break minutes, Hourly rate
Limitations
Everyday results are quick planning checks. Unit choices, rounding, labels, measurements, local prices, and real-world constraints can change the final decision.
Last reviewed
June 6, 2026
Cite this page
Toolkit Shelf. Time Duration Calculator. Last reviewed June 6, 2026. https://toolkitshelf.com/tools/time-duration-calculator
FAQ
Common questions
How do I calculate hours between two times?
Subtract the start time from the end time. This calculator also subtracts break minutes and shows decimal hours.
Can this calculate overnight shifts?
Yes. If the end time is earlier than the start time, the calculator treats the end time as the next day.
Why use decimal hours?
Decimal hours are useful for timesheets, invoices, payroll estimates, and hourly billing.
Why might the real-world result differ?
Match the result to the task type: shopping tools depend on the same unit and usable quantity, home-project tools depend on field measurements and waste, date/time tools depend on counting rules, and conversion tools depend on the unit system.
Should I round the result?
Round for readability after checking the formula and units. Keep more precision when the result feeds another calculation, and add a task-specific buffer only when shortage, waste, or timing risk matters.
Why might another calculator show a different output?
Different tools may use different rounding, assumptions, default rates, methods, formulas, or input timing. Compare the visible method and inputs before relying on the output.