Time duration calculator

Hours and minutes between two times, including overnight shifts.

Formula Date & time

Duration (h:mm)

Decimal hours: 8.50 h
Minutes: 510 min

How it works

The start time is subtracted from the end time. If the end is earlier than the start, the end is taken to be on the next day, so 22:00 to 06:00 is 8 hours.

Any break is then subtracted. Decimal hours are useful for timesheets and pay: 8 hours 30 minutes is 8.5 hours.

The calculation uses clock times only; a daylight saving change during an overnight shift is not counted.

Formula

Duration = end − start (+ 24 h if end < start) − break
Decimal hours = hours + minutes ÷ 60

Worked example

From 09:00 to 17:30 is 8 hours 30 minutes, or 8.5 decimal hours. With a 30-minute break it is 8:00. A night shift from 22:00 to 06:00 is also 8:00.

Questions people ask

How do I calculate hours worked overnight?

Enter the start and end times as they are. When the end time is earlier, the calculator adds 24 hours, so 22:00 to 06:00 is 8 hours.

How do I convert minutes to decimal hours?

Divide the minutes by 60. 15 minutes is 0.25 hours, 30 minutes is 0.5 and 45 minutes is 0.75.

What about daylight saving time changes?

They are not counted. On the night the clocks change, an overnight shift is one hour longer or shorter than shown.