Time Calculator
Time Calculator adds or subtracts two durations expressed in hours, minutes and seconds, and shows the result both as a tidy h/m/s figure and as a total number of seconds.
It is handy for adding up logged hours, working out elapsed time, or combining lap and split times.
How to use Time Calculator
- 1
Enter duration A
Type the hours, minutes and seconds of the first duration.
- 2
Choose add or subtract
Pick whether to add the second duration or subtract it.
- 3
Enter duration B and read the result
The combined time appears instantly, in h/m/s and in seconds.
How durations are combined
Each duration is converted to seconds — hours × 3600 plus minutes × 60 plus seconds — then added or subtracted, and the total is converted back into hours, minutes and seconds.
Subtraction can produce a negative result, which the tool shows with a minus sign, so you can see when duration B is longer than duration A.
When to use it
Use it to total time entries on a timesheet, add up cooking or workout intervals, or find how much time is left before a deadline.
Because it works purely with durations, it does not depend on a clock time or date — for the gap between two calendar dates, use the date difference calculator instead.
Frequently asked questions
- Can the result be negative?
- Yes. If you subtract a longer duration from a shorter one, the result is shown as a negative time.
- Does it handle values over 60?
- Yes. You can enter, say, 90 minutes; it is normalised correctly when the total is displayed.
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