Tiny Toolkit

Time Duration Calculator — Add & Subtract Time Online

Enter two time durations in hours, minutes, and seconds to add or subtract them instantly. The result is displayed in h:mm:ss format alongside the equivalent total in seconds and minutes. Useful for calculating total workout time, meeting lengths, video edit durations, or any time-arithmetic task.

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Frequently Asked Questions

Can I subtract durations to get a negative result?
Yes. If you subtract a longer duration from a shorter one, the result is shown as a negative time. This is useful when calculating time overruns.
How do I convert hours to minutes or seconds?
Enter the duration (e.g. 2h 30m 0s) and the result shows the equivalent in seconds and minutes. You can also add a zero-length second duration to convert a single duration.
Is there a limit on the duration I can enter?
No practical limit. You can enter large values in the hours field (e.g. 10,000 hours) and the calculator will sum or subtract them correctly.

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