Hours calculator

Find the duration between a start and end time, including overnight shifts, in hours and minutes.

Start time End time

Duration: -

Formula and algorithm

Duration = end time − start time, in minutes.
If the end time is earlier than the start, it is treated as the next day (overnight).
The result is shown as hours and minutes, and as decimal hours for payroll.

Input: 09:00 to 17:30

Output: 8h 30m (8.5 hours)

510 minutes between the two times.

Input: 22:00 to 06:00

Output: 8h 0m (8 hours)

Crosses midnight, so 8 hours total.

Input: 12:15 to 12:45

Output: 0h 30m (0.5 hours)

30 minutes.

Does it handle overnight times?

Yes. If the end is before the start, it assumes the end is on the next day.

What are decimal hours?

The duration as a single number (e.g. 8h 30m = 8.5), useful for timesheets and pay.

Does it use a 24-hour clock?

Enter times in 24-hour HH:MM format; most browsers show a clock picker.

Updated: June 7, 2026