Duration Calculator
Add up multiple HH:MM:SS durations and see the total, average and breakdown.
Paste a list of durations (HH:MM:SS or HH:MM, one per line) and the calculator sums them, shows an average and lists each line's parsed value. Hours can exceed 24 — useful for tracking total project time.
Common use cases
- Sum daily timesheet entries into weekly totals
- Add up movie or playlist runtimes
- Total race split times or workout durations
- Compute time spent across multiple meetings
Frequently asked questions
Which input formats are accepted?▾
Two-part HH:MM (e.g. 1:30) and three-part HH:MM:SS (e.g. 1:30:45). Decimal seconds are accepted but rounded in the totals display.
Can hours be more than 24?▾
Yes — totals can be hundreds of hours, useful for cumulative project time.
Why is one of my lines marked invalid?▾
Lines must contain only digits and colons in the right pattern. Stray text, extra colons or empty fields are flagged so the rest of the total stays correct.
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