How this time duration calculator works
The calculator subtracts the start time from the end time and shows the elapsed time in hours, minutes and decimal hours. Time-only mode uses wall-clock times. Date and time mode uses the browser-local datetimes entered.
Crossing midnight
If the end time is after midnight on the next day, turn on overnight mode. Same start and end time with overnight mode is treated as a full 24-hour duration.
Decimal hours
Decimal hours convert minutes into a fraction of an hour. For example, 7 hr 30 min is 7.50 decimal hours.
Time-only vs datetime mode
Time-only mode is best for a simple wall-clock span. Datetime mode is useful when the period covers more than one date, but this version does not add a timezone selector.
What this tool does not include
This tool does not subtract breaks, calculate payroll rules, decide overtime, convert time zones or create calendar schedules.
Key terms and assumptionsShort notes about wall-clock time, overnight mode, decimal hours and timezone scope.
- Wall-clock time
- Time-only mode compares the two times on a simple clock and does not know about daylight saving transitions.
- Overnight mode
- When the end time is before or the same as the start time, overnight mode treats the end as the next day.
- Datetime mode
- Full date and time inputs use browser-local datetime values. This version does not include a timezone selector.
- Decimal hours
- Decimal hours are total displayed minutes divided by 60 and rounded to two decimal places.
- No payroll rules
- The result is elapsed time only. It does not subtract breaks, calculate overtime or apply payroll rules.
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Browse the Date & Time tools hub for related Date & Time tools.
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FAQs
How do I calculate hours between two times?
Enter the start time and end time. The calculator subtracts the start from the end and shows hours, minutes and decimal hours.
How do I handle times after midnight?
Turn on the overnight option so the end time is treated as the next day.
What are decimal hours?
Decimal hours convert minutes into a fraction of an hour, such as 7 hr 30 min = 7.50 hours.
Does this include breaks?
No. Use the Time Card Calculator when break duration should be subtracted.
Does this handle time zones?
No. Use a time zone converter for time zone conversion.
Does daylight saving affect results?
Time-only mode uses wall-clock times. Datetime mode may reflect local daylight saving behavior if browser datetimes are used.
Can the result be negative?
No. This version warns when the end time is before the start time instead of showing a negative duration.