Time Duration Calculator

How to calculate time duration

1. Convert both times to a 24-hour clock (2:30 PM = 14:30).
2. If the end time is earlier than the start time, the period crosses midnight, so add 24 hours to the end time.
3. Subtract the start time from the end time, then subtract any unpaid break.

Worked example

A shift from 9:00 AM to 5:30 PM is 17:30 − 9:00 = 8 hours 30 minutes. After a 30-minute unpaid lunch, the time worked is 8 hours, or 8.00 decimal hours.

An overnight shift from 10:00 PM to 6:15 AM: 6:15 + 24:00 = 30:15, and 30:15 − 22:00 = 8 hours 15 minutes.

Converting minutes to decimal hours

Payroll systems usually need hours as a decimal. Divide the minutes by 60:

Minutes	Decimal hours
15	0.25
20	0.33
30	0.50
40	0.67
45	0.75
50	0.83

So 7 hours 45 minutes is 7.75 hours. Multiply decimal hours by your hourly rate to work out pay.

Frequently asked questions

How do I calculate hours between two times?

Subtract the start time from the end time using a 24-hour clock. If the result is negative, add 24 hours because the period ends the next day.

How do I handle overnight shifts?

Enter the start and end times normally. The calculator notices that the end is earlier than the start and adds a day.

What is 8 hours 45 minutes in decimal?

8.75 hours, because 45 minutes is 45 ÷ 60 = 0.75 of an hour.

Can I calculate durations longer than 24 hours?

Yes. Use the Extra full days box to add whole days between the start and end times.

Does it account for daylight saving time?

No. On the nights clocks change, a shift can be an hour longer or shorter than the calculator shows.