Duration calculator
Add a list of durations and subtract breaks without wrapping at 24 hours.
- 1Add input
- 2Review and run
- 3Get your result
Tool input and files are processed in this browser without being uploaded.
Before you start
Paste one duration per line to total work logs, media clips or other elapsed time. Use H:MM:SS or M:SS (minutes:seconds); prefix a line with - to subtract a break. The total keeps hours above 24.
How to use this tool
- Paste or type one duration per line. A leading minus sign subtracts that duration.
- Check the total, added and subtracted amounts, then expand the line-by-line running totals if needed.
- Copy the total or exact seconds, or download the total as TXT.
Supported inputs and limits
Each nonblank line must be H:MM:SS or M:SS with whole seconds. In the two-part form, 1:30 means 1 minute 30 seconds; write 1:30:00 for 1 hour 30 minutes.
Up to 500 nonblank lines and 40,000 characters; each hour or minute count is at most six digits. Times of day, dates and fractions of seconds are not accepted.
Calculation runs in your browser; no account or upload is needed.
Worked example
Example input
01:45:00 00:30:00 02:15:00 -00:15:00
Example options
{}Example output
04:15:00
When something does not work
Check the reported line. Use H:MM:SS or M:SS with minutes and seconds from 00 to 59, and prefix - only when subtracting.
Frequently asked questions
Does 1:30 mean one hour and 30 minutes?
No. Two parts mean minutes:seconds, so 1:30 is 1 minute 30 seconds. Use 1:30:00 for one hour 30 minutes.
What happens after 24 hours or when the total is negative?
Elapsed hours never wrap at 24. A minus sign on the total means deductions exceed additions.
Can I paste clock times or dates?
No. Enter elapsed durations only; this tool does not calculate time between clock times or dates.
Documentation & further reading
Related tools
Timestamp converter
Convert integer Unix timestamps and known-offset dates, with UTC and IANA-zone display.
Time zones and UTC formatting
Resolve time zones and daylight-saving ambiguity, or format an instant in UTC.
Days between dates
Find out just how far apart two dates are.
Add or subtract dates
Add or subtract time from a chosen date.