Add Time Calculator
Type two durations and press Calculate to add them. It is built for totalling hours and minutes without a calculator mistake.
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The formula
Total = time 1 + time 2, carrying every 60 seconds into minutes and every 60 minutes into hours.
Why adding time is awkward
Normal addition works in tens, but time works in sixties. 3 hours 50 minutes plus 2 hours 25 minutes is 6 hours 15 minutes, because 75 minutes carries over as an hour and 15 minutes.
A weekly timesheet
To total a week, add Monday and Tuesday, then add the result to Wednesday, and so on. Or convert each day to decimal hours using the hours calculator and add those.
Examples to check
Type these into the calculator above to see how it behaves. Every result below was produced by the same calculator code that runs on this page.
| What you enter | What you get |
|---|---|
| First time (hh:mm or hh:mm:ss): 1:30:00; Add (+); Second time (hh:mm or hh:mm:ss): 0:45:30 | Result: 2:15:30 |
| First time (hh:mm or hh:mm:ss): 3:50; Add (+); Second time (hh:mm or hh:mm:ss): 2:25 | Result: 6:15:00 |
| First time (hh:mm or hh:mm:ss): 8:00; Subtract (-); Second time (hh:mm or hh:mm:ss): 0:45 | Result: 7:15:00 |
| First time (hh:mm or hh:mm:ss): 0:59:59; Add (+); Second time (hh:mm or hh:mm:ss): 0:00:01 | Result: 1:00:00 |
Add Time Calculator: frequently asked questions
How do I add time on a normal calculator?
Convert everything to minutes, add, then divide by 60 for hours and use the remainder as minutes.
Does it show days if the total passes 24 hours?
Yes. Totals over 24 hours also show the number of days and the leftover time.
Does it take leap years into account?
Yes. Calculations use real calendar dates, including leap days and the different lengths of months.
Is what I enter in this calculator saved or sent anywhere?
No. The calculation runs in your browser, so what you enter is not sent to our servers. We only count, anonymously, whether a tool ran successfully.
Is this calculator free to use?
Yes. It is free, needs no sign-up and has no usage limit.
Last reviewed: October 3, 2026