Time Duration Calculator

Calculate elapsed hours and minutes between two 24-hour clock times, including intervals that cross midnight.

Calculate elapsed clock time

7 h 45 minTotal elapsed minutes: 465An earlier end time is treated as the next day.

How this tool works

Clock subtraction becomes error-prone when minutes require borrowing or an interval crosses midnight. This calculator converts each time to minutes after midnight, applies a one-day rollover where needed, and converts the difference back.

Elapsed minutes equal end-hour×60+end-minute minus start-hour×60+start-minute. If negative, adding 1,440 minutes represents an end time on the following day.

How to use it

  1. Enter start hour and minute using the 24-hour clock.
  2. Enter end hour and minute in the same format.
  3. Read elapsed hours, minutes, and the total-minute check.

Worked examples

Same-day duration

Input
09:30 to 17:15
Output
7 hours 45 minutes

The start is 570 minutes after midnight and the end is 1,035, leaving an elapsed difference of 465 minutes.

Crossing midnight

Input
22:30 to 01:15
Output
2 hours 45 minutes

Because the end clock time is earlier, it is treated as the next day. Adding a day gives a 165-minute interval.

Limitations

  • Identical times are reported as zero rather than a full 24 hours.
  • The calculator does not handle dates, time zones, or daylight-saving changes.