How it works
Because the inputs are full date-and-time values rather than just clock times, spans that cross midnight or run over several days work correctly without any special handling — pick a start and end and the calculator subtracts one from the other.
duration = end date/time − start date/time
decimal hours = total minutes ÷ 60
Worked example
9:00 AM to 5:30 PM the same day.
- Elapsed time: 9:00 AM to 5:30 PM = 8 hours 30 minutes.
- Total minutes: 8 × 60 + 30 = 510 minutes.
- Decimal hours: 510 ÷ 60 = 8.50 hours.
9:00 AM to 5:30 PM = 8h 30m — 510 minutes, or 8.50 decimal hours.
Common questions
Can the end time be on a different day than the start?
Yes — because both inputs are full dates and times, not just clock times, you can pick an end time on the next day (or several days later) and the calculator handles overnight or multi-day spans correctly.
Why does it show decimal hours as well as hours and minutes?
Decimal hours are useful for timesheets and billing, where a duration like 8 hours 30 minutes is usually entered as 8.5 rather than "8:30."