Time Duration Calculator
How long is it between two times? Enter a start and end time to get the duration in hours and minutes, in decimal hours, and in total minutes. Overnight spans are handled automatically.
Your numbers
Result
- Decimal hours
- 8.5
- Total minutes
- 510
| Unit | Value |
|---|---|
| Hours and minutes | 8:30 |
| Decimal hours | 8.50 h |
| Total minutes | 510 |
How the duration is worked out
The calculator subtracts the start time from the end time. From 9:00 AM to 5:30 PM is 8 hours 30 minutes. If the end time is earlier than the start — an overnight span like 10:00 PM to 6:00 AM — it adds 24 hours so the result is still correct (8 hours).
Hours and minutes vs decimal
The duration shows both ways. 8:30 means 8 hours and 30 minutes; the decimal form is 8.5 hours (minutes ÷ 60). Timesheets, billing and payroll use the decimal — and 8:30 is not "8.30", a common slip the calculator saves you from.
Twelve- or twenty-four-hour time
Enter times however you like: 12-hour with AM/PM (5:30 PM) or 24-hour (17:30). Both are accepted for either field, so you can mix a morning AM time with an afternoon 24-hour time and still get the right span.
Frequently asked questions
Sources
- Clock arithmetic (time-of-day durations)
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