How do I work out the time between two times?

Convert both times to minutes since midnight, subtract the start from the end, then convert the result back to hours and minutes. If the end time is earlier than the start time, the duration crosses midnight, so add 24 hours.

What are decimal hours?

Decimal hours express minutes as a fraction of an hour. For example, 7 hours and 30 minutes is 7.5 decimal hours. Payroll and timesheets often use decimal hours, because they are easy to multiply by an hourly rate.

Does this handle overnight shifts?

Yes. If the end time is before the start time, the calculator assumes the duration runs past midnight into the next day and adds 24 hours, so an overnight shift from 10:00 pm to 6:00 am correctly returns 8 hours.

Time Duration Calculator

Work out how much time has passed between two times. Enter a start time and an end time, and the calculator shows the duration in hours and minutes, the total minutes, and decimal hours for payroll or timesheets. It handles durations that cross midnight, so overnight shifts are calculated correctly.

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Start time

End time

8 hours 30 minutes

Total minutes510

Decimal hours8.5

How the duration is worked out

Each time is converted to the number of minutes since midnight. The start is subtracted from the end to give the duration in minutes, which is then converted back to hours and minutes. If the end time is earlier than the start time, the duration is assumed to run past midnight, so 24 hours are added.

Worked example

A shift runs from 9:00 am to 5:30 pm. That is 540 minutes since midnight for the start and 1,050 for the end. The difference is 510 minutes, which is 8 hours and 30 minutes, or 8.5 decimal hours.

An overnight shift from 10:00 pm to 6:00 am has an end time earlier than the start, so 24 hours are added. The result is 8 hours.

Why decimal hours matter

Payroll systems usually multiply hours by an hourly rate, and that is easier with decimal hours than with hours and minutes. For example, 8 hours and 30 minutes is 8.5 hours, so at $25 an hour that shift is worth $212.50.

Frequently asked questions

Does it handle overnight shifts?

Yes. If the end time is before the start time, the calculator adds 24 hours, so an overnight shift returns the correct duration.

How do I convert minutes to decimal hours?

Divide the minutes by 60. So 30 minutes is 0.5 hours, and 15 minutes is 0.25 hours.

Who this calculator is for

This calculator is for anyone finding the duration between two times or dates, for scheduling, timesheets or planning.

What this calculator assumes

The two times or dates you enter.
Standard 24-hour and calendar arithmetic.
It does not adjust for time zones or daylight saving unless stated.
Results are shown in the units selected.

Related calculators

Hours Calculator: add up hours and minutes.
Work Hours and Timesheet Calculator: full timesheet with breaks.
Time Calculator: add or subtract time.
Business Days Calculator: working days between dates.

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