How to use this calculator
Enter whole hours and the remaining 0–59 minutes for each duration. Select Add to combine them or Subtract to remove the second from the first. These inputs represent durations, not clock times.
Formula
total minutes = (H₁ × 60 + M₁) ± (H₂ × 60 + M₂)
Worked example
2 hours 45 minutes plus 1 hour 30 minutes is 4 hours 15 minutes. Subtracting 1 hour 30 minutes instead gives 1 hour 15 minutes. A 30-hour duration remains 30 hours rather than wrapping to a clock time.
Assumptions and limits
Results can be negative. The sign applies to the whole duration. Decimal results are displayed with up to four places; the minutes and hours-and-minutes totals remain exact.
Frequently asked questions
Can the result exceed 24 hours?
Yes. Durations are elapsed amounts and can span many days. This tool does not wrap totals after midnight.
Are the results decimal hours or clock time?
Both are shown where useful. Decimal hours divide minutes by 60; a duration such as 7 h 30 min is 7.5 hours.
Are my times uploaded?
No. Calculations run in your browser. Saved inputs remain on this device until reset or cleared in browser site-data settings.
Clock calculations use wall-clock minutes, without time zones or daylight-saving adjustments. An earlier end time means next day in automatic mode. Equal start and end times mean zero, unless Next day is selected.