Time Calculator
Enter two durations and choose add or subtract.
This result is an estimate only. Double-check important figures before relying on them.
How it is calculated
- Convert each duration to seconds
- Add or subtract
- Convert back to hours, minutes and seconds
For clock times rather than durations, use the elapsed time calculator.
Worked example
2 h 45 min + 1 h 30 min:
- 4:15:00
- 4.25 hours, 255 minutes
Why your number may differ
Durations are not clock times. A result over 24 hours is shown as total hours, not days and a time.
Frequently asked questions
How do I add hours and minutes?
Add the minutes first. If they pass 59, carry 1 hour for every 60 minutes, then add the hours.
How do I turn the result into a decimal?
Divide the minutes by 60. 4 hours 15 minutes is 4.25 hours.
Can it show a negative time?
No. Swap the two durations if the answer would be below zero.