Time Duration Calculator
Add and subtract hours, minutes and seconds with a running total — perfect for timesheets, video edits, workouts and cooking times. Free, instant and fully in your browser.
Total (hours : minutes : seconds)
How to use the Time Duration Calculator
- Enter your durations. Type hours, minutes and seconds into each row — values like 90 minutes or 2.5 hours are fine, the tool normalizes them automatically.
- Add or subtract. Click the +/− button on a row to switch it between adding to and subtracting from the running total. Use ＋ Add duration for more rows.
- Read the total. The sum updates as you type, shown as hours:minutes:seconds plus decimal hours, total minutes and total seconds. Copy it with one click.
About this tool
This free time duration calculator adds and subtracts lengths of time the way a normal calculator adds numbers — but in base 60, so you never have to carry minutes into hours by hand. It is ideal for totaling work hours on a timesheet, summing lap or split times, adding up video or podcast clip lengths for an edit, combining cooking steps, or working out how much flight time a multi-leg trip adds up to. The decimal-hours output (e.g. 7:45 = 7.75 hours) is exactly what payroll and billing systems expect.
You can mix units freely: 1 hour 90 minutes, 200 seconds, or 1.5 hours all work and are normalized into a clean total. Subtracted rows can even push the total negative, which is shown clearly with a minus sign. Everything is calculated locally in your browser — nothing you type is uploaded or stored.
Frequently asked questions
Can I enter more than 59 minutes or seconds?
Yes. Fields don't have to be "clock legal" — 90 minutes, 500 seconds or 36 hours are all accepted and automatically normalized, so 1 h 90 min becomes 2:30:00 in the total.
Can I use decimal values like 1.5 hours?
Yes. Decimals work in every field: 1.5 hours is treated as 1 hour 30 minutes, and 0.5 minutes as 30 seconds. The total is computed exactly and displayed to the nearest fraction of a second.
How do decimal hours work?
Decimal hours express the total as a plain number of hours: 7 hours 45 minutes is 7.75 because 45 minutes is 45/60 = 0.75 of an hour. Payroll, invoicing and project-tracking software usually want this format.
What does a negative total mean?
If your subtracted rows are longer than your added rows, the total goes below zero and is shown with a minus sign — useful for questions like "how far short of 40 hours am I this week?"