Time Duration Calculator

How long is it between two times?

Result

8 h 25 min
505
8.42

How it is calculated

The tool converts each clock time to minutes after midnight and subtracts: minutes = end − start. If the result is negative, the end is taken to be on the next day and 1,440 minutes (24 hours) are added. The duration is then shown as hours and minutes, as a total number of minutes, and as decimal hours, minutes / 60, rounded to two places. The times are 24-hour values (HH:MM). Only clock times are used, no dates, so the longest possible result is just under 24 hours, and identical start and end times give zero, not 24 hours. For spans over a day or across dates, use a date difference tool.

Worked example

From 22:15 to 06:40. Start is 22 × 60 + 15 = 1,335 minutes and end is 6 × 60 + 40 = 400 minutes. The difference 400 − 1,335 is negative, so add 1,440 to get 505 minutes. That is 8 h 25 min, or 505 / 60 = 8.42 in decimal hours.

Try this example →

Common mistakes

  • Mixing 12-hour and 24-hour entries, such as typing 6:40 when 18:40 is meant.
  • Reading 8.42 as 8 hours 42 minutes; it is 8 hours and about 25 minutes.
  • Expecting 24 hours when the start and end time are the same: the tool returns zero.
  • Using it for spans of more than one day, which the clock times alone cannot express.
  • Forgetting that the overnight rule assumes exactly one midnight, with no daylight saving shift.

About this calculator

This calculator finds the elapsed time between a start and end clock time, handling the awkward parts automatically: it correctly carries over the hour when minutes go negative, and it accounts for the case where the end time is on the following day (like an overnight shift). The result is given three ways — hours and minutes, total minutes, and decimal hours — because different situations call for different formats.

It's used constantly for payroll and timesheets, where hourly wages need to be multiplied by decimal hours rather than a clock-style duration; by shift workers checking how long a night shift actually runs; and by anyone timing an activity, meeting or commute where doing the subtraction by hand risks an off-by-one-hour mistake around the top of the hour.

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