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Everyday maths / Free tool

Hours and time duration calculator

Find working hours between clock times, subtract breaks and handle overnight shifts.

Your numbersLive result
Choose the question you want to answer.
Required. 24-hour clock time.
Required. Use hours and minutes on a 24-hour clock.
Required. 0 or more. Whole numbers only. Maximum 2,880. Whole minutes; no longer than the shift.

Example values are prefilled. Change any number to calculate.

Hours after the break

8 hours

Hours component
8
Minutes component
0
Elapsed minutes
510

Uses clock times with an explicit same-day or next-day choice. Breaks are entered in whole minutes. This is clock arithmetic, not timezone- or daylight-saving-aware elapsed time.

Your inputs stay in this browser.

The working behind the answer

How to use this calculator

Enter both clock times and explicitly choose whether the end falls on the same or next calendar day. Breaks are entered in whole minutes. The main answer is decimal hours, with separate hours and minutes below it for easy checking.

The formula

Start and end on the same day

Working minutes = end time − start time − break

End on the next day

Working minutes = end time + 24 hours − start time − break

A worked example

From 09:00 to 17:30 is 8 hours 30 minutes. Subtract a 30-minute break and the result is 8 hours. A 22:00–06:00 overnight shift with the same break gives 7.5 hours.

Good to know

This is clock-time arithmetic. It does not account for timezone changes, daylight-saving transitions, overtime rules or automatic paid breaks. In next-day mode an end time later on the clock can represent a shift longer than 24 hours.

Common questions

Is 7.5 hours the same as 7 hours 50 minutes?

No. Half an hour is 30 minutes, so 7.5 hours is 7 hours 30 minutes.

What if the break exceeds the shift?

The tool asks you to correct the break instead of showing a negative working duration.