How to use this calculator
- Enter or choose start date (optional).
- Enter or choose start time.
- Enter or choose end date (optional).
- Enter or choose end time.
- The duration updates as you type. Use Copy result or Share to keep it.
Method
Duration = (End date − Start date) × 24 h + (End time − Start time); without dates, add 24 h when the end time is earlier than the start; Decimal hours = Hours + Minutes ÷ 60
- Dates
- calendar dates; leap days are counted
- Times
- 24-hour clock times
Worked example
- 17:45 − 09:15 = 8 hours and 30 minutes.
- Decimal hours = 8 + 30 ÷ 60 = 8.5.
- In minutes: 8 × 60 + 30 = 510.
From 9:15 to 17:45 is 8 hours 30 minutes, or 8.5 hours.
What the result means
Decimal hours are what timesheets and payroll multiply by an hourly rate: 8 h 30 min is 8.5 hours, not 8.30.
Assumptions and limits
- Clock times are in the same time zone.
- Daylight-saving changes are not applied: a span across a clock change will be an hour off.
- Breaks are not deducted.
Questions
How do I convert minutes to decimal hours?
Divide by 60. 15 min = 0.25 h, 30 min = 0.5 h, 45 min = 0.75 h.
How do I time a night shift?
Enter the start and end times with no dates. If the end is earlier than the start, it is counted as the next morning: 22:30 to 06:15 is 7 h 45 min.