Time & dates
Combine two durations or subtract one from another. Enter hours, minutes and optional seconds separately, choose the operation, and read the resulting duration without doing the carrying by hand.
Enter two durations in hours, minutes and seconds, then choose addition or subtraction. These are durations, not clock times. The result normalises overflowing minutes and seconds and preserves a negative sign when needed.
Adding 2 hours 45 minutes and 1 hour 30 minutes gives 4 hours 15 minutes. Subtracting 3 hours from 1 hour gives a negative duration of 2 hours.
A duration is an amount of time, such as 2 hours 40 minutes. A time of day, such as 14:40, identifies a position on a clock. This calculator operates on durations. Adding 3 hours to 23 hours produces a 26-hour duration; it does not wrap around and become 02:00 on the following day.
For addition, the two minute amounts may pass the hour boundary. For example, 50 minutes plus 35 minutes is 85 minutes, which becomes 1 hour 25 minutes. Seconds carry into minutes in the same way. Larger minute and second entries are normalised into a readable duration.
Subtraction is useful for a planned time budget, a remaining allowance or the difference between two estimates. Put the starting amount first and the amount to remove second. A 4-hour allowance minus 1 hour 45 minutes leaves 2 hours 15 minutes. Check the order when a negative answer appears.
A negative result means the second duration exceeded the first. It can represent an overrun rather than an input error. Keep the sign with the entire duration when recording that balance; do not interpret a negative hour field and a positive minute field as independent amounts.
Enter minute values in the minute field and decimal hours in the decimal hours converter. For example, 1.5 decimal hours should first become 1 hour 30 minutes. If the task is to find the time between an actual start and finish, use the work hours or time duration calculator instead.
The result is arithmetic. It does not decide whether travel, breaks, waiting or overtime should count in a work agreement. Label what each input represents so a colleague reviewing the total can reproduce the same calculation.
Worked example
A 2-hour 50-minute task plus a 1-hour 35-minute task totals 4 hours 25 minutes. The extra 60 minutes carry into one additional hour.
No. The output is a duration and can contain more than 24 hours.
The second duration is larger than the first in a subtraction. It shows how far the starting amount was exceeded.
This tool adds durations. For a dated start and finish comparison, use the time duration calculator.