Time Calculator
Add or subtract hours, minutes and seconds — get the total as h:mm:ss, in decimal hours and in words.
About this tool
Enter two durations in hours, minutes and seconds and choose add or subtract. The calculator carries minutes and seconds over correctly (90 minutes becomes 1 hour 30 minutes), shows the result as h:mm:ss, in decimal hours for timesheets and invoices, in words, and as total minutes and seconds. Hours are not wrapped at 24, so you can add up long durations; results over a day are also shown in days.
Frequently asked questions
Add the hours and the minutes separately, then carry every 60 minutes over as one hour. Example: 2 h 45 min + 1 h 30 min = 3 h 75 min = 4 h 15 min. The calculator does this for seconds too.
Divide the minutes by 60. 15 min = 0.25 h, 30 min = 0.5 h, 45 min = 0.75 h and 20 min ≈ 0.333 h. So 4 h 15 min is 4.25 hours — the format most timesheets and invoices use.
The result is negative and shown with a minus sign, for example 1:00:00 − 2:30:00 = −1:30:00 (−1.5 hours). Swap the two times if you want the difference as a positive duration.
Yes. Minutes and seconds above 59 are carried over, so 0 h 90 min is read as 1:30:00. This makes it easy to add up a list of minutes without converting them first.
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