Time Duration Calculator
Free, locally-processed time duration calculator for fast and secure results.
Runs locally in your browser
Your inputs are processed locally in your browser and are not uploaded or stored by us.
Calculate the exact duration in hours and minutes between a start time and an end time.
How to use the Time Duration Calculator
- Enter the start clock time.
- Enter the end clock time.
- Choose whether the end time occurs on the same day or the next day.
- Select Calculate.
Calculation methodology
Duration = End Time − Start Time
The calculator evaluates the total minutes since midnight for both times. If the end time is set to "next day", exactly 24 hours are added to the end time before subtraction.
Worked example
Start time22:00
End time02:00
End time is onNext day
22:00 to midnight = 2 hours
Midnight to 02:00 = 2 hours
Result: 4 hours, 0 minutes
Notes
- Can I enter the same time? Yes. If you enter 09:00 to 09:00 on the "same day", the duration is 0 hours. If you select "next day", the duration is exactly 24 hours.
- What if the end time is earlier on the same day? The calculator will reject this input as impossible.