Time Duration Calculator
Enter a start and end time to get the exact elapsed duration in hours and minutes, or add/subtract a duration from a given time — useful for timesheets, shift calculations, or scheduling.
Calculators Runs entirely in your browser
All calculations happen on your device — nothing is sent to a server.
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- Result
- 00:00:00
What this tool does
Adds or subtracts durations in hours, minutes and seconds, giving a properly carried result.
When to use it
- Totalling hours logged across several sessions.
- Working out remaining time by subtracting what has elapsed.
- Adding up the lengths of audio or video clips.
- Totalling the time several tasks took.
How to use it
- Choose the "Operation": "Add" or "Subtract".
- Enter the "Hours", "Minutes" and "Seconds" for each duration.
- Read the "Result".
A practical example
Input
Adding two hours 45 minutes to one hour 30 minutes.
Output
Four hours 15 minutes — carried properly rather than reported as three hours 75 minutes.
Limitations
- This handles durations rather than times of day; for the gap between two clock times in different zones, use the Timezone Converter.
- A subtraction producing a negative value is shown as it is, so mind the order of your inputs.
- Days are not treated as a unit; long durations are reported in hours.
Privacy and processing
All calculations happen on your device and nothing is sent to a server.
Technical notes
- Carrying between seconds, minutes and hours is automatic, so you never get a result containing more than 59 minutes or seconds.