Time Addition Calculator

Add up hours, minutes and seconds — or subtract them — row by row.

—

—Decimal hours

—Total minutes

—Total seconds

—Days

How to add times

Type hours, minutes and seconds in each row. Blank boxes count as 0, and values over 60 are fine (90 minutes works).
Switch a row to − to subtract it.
Press + Add row for more entries. The total updates as you type and is saved in your browser.

How time addition works

Convert everything to seconds, add, then convert back: hours = total ÷ 3600, minutes = remainder ÷ 60.

Example: 1:30:00 + 0:45:00 + 2:15:30 = 5,400 + 2,700 + 8,130 = 16,230 s = 4:30:30. Note how 30 + 45 + 15 minutes carries over into an extra hour.

Frequently asked questions

How do you add hours and minutes together?

Add the hours and minutes separately, then for every 60 minutes carry 1 hour. 2 h 50 min + 1 h 25 min = 3 h 75 min = 4 h 15 min.

Can I enter decimal hours?

Yes. Type 1.5 in the hours box for 1 hour 30 minutes, or type 1:30 there.

Why does a total show more than 24 hours?

Durations are not clock times, so the total keeps counting past 24 (for example 30:15:00). The Days box shows the same total in days.

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