Toolkit Shelf
Find

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.

Method and assumptions documentedFree toolSource note included

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.

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.

ResultNet duration
InputsStart time, End time, Break minutes, Hourly rate
FormulaTime duration formula

Formula

Time duration formula

Net duration = end time - start time - break time

If the end time is earlier than the start time, the calculator treats it as ending the next day.

How to use

Steps

  1. Enter the start time.
  2. Enter the end time.
  3. Add unpaid break minutes if needed.
  4. 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

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

NISTDefines time as either the designation of an instant or the interval between two events.

Benchmarks

How to read the result

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

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.

Review record

Catalog QA baseline on June 6, 2026. This date marks the catalog-wide automated and editorial QA baseline, not a tool-specific expert review.

Cite this page

Toolkit Shelf. Time Duration Calculator. 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.