Use this time duration calculator to find how much time passes between a start time and an end time. It returns the duration in hours and minutes and automatically handles a finish after midnight.
How to calculate duration between two times
Convert the start and end clock readings to the same basis, then subtract the start from the end. This calculator uses after midnight, which avoids mixing base-60 with decimal arithmetic.
Use the time the interval began and the time it ended.
If the end is earlier on the clock, it is treated as the next .
The main answer uses hours and minutes; details also show decimal hours and total minutes.
Time duration across midnight
Start = 10:45 PM
End = 6:20 AM the next
Elapsed time = End − Start
Elapsed time = 7 35
Decimal hours = 7.58 h
Total minutes = 455 min
Decimal hours and total minutes
Decimal hours express the complete duration as a fraction of an hour. Divide elapsed by 3,600 s/h. In the overnight example, 7 35 becomes 7.58 h after display rounding; it is not 7.35 because clock minutes are sixtieths of an hour.
Total minutes divide the same duration by 60 s/min, producing 455 min. These are equivalent forms of the raw duration; they do not apply break or payroll rules.
When two clock times are not enough
Two clock readings can describe a same- interval or one overnight rollover. Use a date-duration calculator when the interval spans explicit dates or more than one . A time-zone tool is needed when the readings come from different zones, and a work-hours calculator is needed for breaks, rounding, multiple shifts, or pay. For clock arithmetic that adds or subtracts a known duration, use the Time Calculator.