How to use the Time Duration Calculator
Enter the start hour, start minute, end hour and end minute and the result appears straight away. Everything runs in your browser, so nothing you type is uploaded.
How the calculation works
The calculator turns both times into minutes after midnight, then subtracts the start time from the end time. 8:45 is 525 minutes and 17:15 is 1,035, so the difference is 510 minutes, or 8 hours 30 minutes. When the end time is earlier than the start, as with a shift from 22:00 to 06:00, it adds 24 hours so the result is not negative.
Payroll and billing
For payroll and billing, remember to take out an unpaid lunch or any other break. A shift from 9:00 to 17:30 with a 30 minute unpaid lunch is 8 hours of paid time. Many employers round to the nearest quarter hour, so 8 hours 20 minutes might be recorded as 8.25 hours. To turn minutes into decimal hours, divide by 60: 20 minutes is 0.33 hours.
The formula
Duration = end minutes − start minutes; add 24 hours for overnight shifts.
Examples
- 09:00 to 17:30
Duration: 8 hours 30 minutes Total minutes: 510
- Night shift 22:00 to 06:15
Duration: 8 hours 15 minutes Total minutes: 495
- 13:45 to 16:10
Duration: 2 hours 25 minutes Total minutes: 145
Limitations and assumptions
Results are estimates for general information. Check assumptions and inputs before relying on them.
Frequently asked questions
How do I calculate time between two times?
Convert both times to minutes since midnight and subtract. Add 24 hours when the end time is on the next day.
Can it handle overnight shifts?
Yes. Set the overnight option to yes and the 24 hours are added for you.
Does it subtract breaks?
No. Use the break time calculator to remove an unpaid break from the total.
How do I turn the result into decimal hours?
Divide the minutes by 60, or use the timesheet decimal converter.