Add durations without treating minutes as decimals
Use hours and minutes, or hours, minutes and seconds. Place a minus sign before a duration to subtract it. The result carries seconds into minutes and minutes into hours.
The calculator also shows decimal hours and total seconds. It adds lengths of time, not dates or clock readings in different time zones.
How to use this tool
- Enter one duration per line, using H:MM or H:MM:SS.
- Start a line with a minus sign to subtract that duration.
- Read the total, then copy or download the results.
Example
Add 1:30 and 2:15, then subtract 0:45. The result is 3:00:00, or 3 decimal hours.
Common questions
Can the result be negative?
Yes. Subtracting more time than you add gives a negative duration. The result keeps that sign.