Time Duration Calculator is now live on Tools.Town — a tool that adds and subtracts time durations expressed in hours, minutes, and seconds, showing the running total and the normalized result (e.g. 3h 45m 20s rather than 225.33 minutes).
Sum up work sessions, calculate total video length, figure out elapsed time from multiple intervals — without a spreadsheet.
What Does It Do?
Add Durations
Enter multiple time values (hours:minutes:seconds) and get the total in a normalized format.
Subtract
Mark any entry as a subtraction — useful for netting out breaks from total session time.
Normalized
Results are always shown as hours:minutes:seconds — no overflow values like '135 minutes'.
Add as many time entries as you need. The running total updates after every entry.
How It Works
Add time entries
Enter each duration as hours:minutes:seconds. Click Add Row to enter more.
Subtract breaks
Toggle any row to subtract — for break periods, or time to deduct from a total.
Read the total
The total appears at the bottom, normalized into hours, minutes, and seconds.
Why We Built It
Time arithmetic is surprisingly fiddly. Adding 1h 45m + 2h 30m + 45m in your head takes effort, and spreadsheets need a special time format to avoid giving you decimals. Time Duration Calculator handles the addition natively, in the format humans think in: hours, minutes, seconds.
Try It Now
Time Duration Calculator
Add and subtract time durations — hours, minutes, seconds. Multiple entries, normalized totals.
Also useful: Date Difference for longer spans, and Timezone Converter for time zone math.
Related Posts
Frequently Asked Questions
Can I add multiple time durations together?
Can I subtract time durations?
Does it handle overflow (e.g. more than 60 minutes)?
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