Add or subtract two durations in hours and minutes.
Time arithmetic is awkward because it is not decimal — there are 60 minutes in an hour, not 100. That means you cannot simply add the numbers as written: 1h 45m plus 2h 30m is not "3h 75m", because 75 minutes rolls over into an extra hour and 15 minutes. This calculator does that carrying and borrowing for you, so the answer always comes out in clean hours and minutes.
When adding, the tool sums the total minutes of both durations, then converts every 60 minutes back into one hour. When subtracting, it borrows an hour (60 minutes) whenever the minutes would go negative. If the second duration is larger than the first, the result is simply shown as a negative duration, which is handy for seeing how far over or under a target you are.
The result is shown two ways. hh:mm is how we read a clock or a timesheet. Decimal hours express the same amount as a single number — 2h 30m becomes 2.5 — which is what you need to multiply time by a pay rate or a price. Payroll and billing systems almost always work in decimal hours, so having both formats side by side avoids conversion mistakes.
Reach for this when you are totalling task times, adding up how long a set of activities took, working out cooking or workout schedules, or checking whether several meetings fit inside a block of free time. For the gap between two clock times such as a shift's start and end, use the hours worked calculator instead.
Add the minutes first; if they total 60 or more, carry the extra into hours. 1h 45m + 2h 30m = 3h 75m = 4h 15m. The calculator handles the carrying automatically.
Subtract minutes and hours separately, borrowing 60 minutes from the hours column if needed. 3h 15m − 1h 45m = 1h 30m. If the second duration is larger, the result is shown as negative.
Decimal hours express minutes as a fraction of an hour: 30 minutes = 0.5, 15 minutes = 0.25. They make it easy to multiply time by an hourly rate. The calculator shows both hh:mm and decimal formats.
Yes. If you subtract a longer duration from a shorter one, the result is negative, shown with a minus sign — useful for tracking whether you are over or under a time budget.
A clock time (like 14:30) is a point in the day; a duration (like 2h 30m) is a length of time. This calculator works with durations. To find the gap between two clock times, use the hours worked calculator.