Time duration calculator
Enter a start time, an end time and an optional break to get the duration in hours and minutes and in decimal hours. From 9:00 to 17:30 with a 30-minute break is 8 h 00, or 8.0 hours.
- Checked on thousands of cases
- Updated November 1, 2026
Duration
- Decimal hours
- 8 h
- Total minutes
- 480 min
Quick challenge
Streak 0Best 0
Test yourself: every answer is computed by the tool, and the wrong choices are the most common traps.
How it works
Formula: Decimal hours = minutes ÷ 60
The calculator converts both times to minutes since midnight, subtracts the start from the end and removes the break. If the end time is earlier than the start time, it counts until the next day (a night shift from 22:00 to 6:00 lasts 8 hours). Decimal hours divide the minutes by 60: 7 h 45 is 7.75 hours, which is the format most timesheets and pay calculations use.
Worked examples
From 9:00 to 17:30 with a 30-minute break
8 h 00 of work.
From 22:00 to 6:00
8 h 00: the count goes past midnight.
7 h 45 in decimal hours
7.75 h (45 minutes = 0.75 h).
Common mistakes
Writing 7 h 45 as 7.45 h.
An hour has 60 minutes: 7 h 45 = 7.75 h.
Subtracting 22 from 6 and getting a negative number.
After midnight, add 24 hours: 8 h 00.
Forgetting the break.
Take it off the total: 8 h 00 for 9:00–17:30 with 30 min.
Minutes to decimal hours
| Minutes | Decimal hours |
|---|---|
| 5 | 0.0833 |
| 6 | 0.1 |
| 10 | 0.1667 |
| 12 | 0.2 |
| 15 | 0.25 |
| 20 | 0.3333 |
| 25 | 0.4167 |
| 30 | 0.5 |
| 40 | 0.6667 |
| 45 | 0.75 |
| 50 | 0.8333 |
| 60 | 1 |
| 75 | 1.25 |
| 90 | 1.5 |
| 120 | 2 |
Frequently asked questions
How do I convert minutes to decimal hours?
Divide by 60. 15 minutes = 0.25 h, 30 minutes = 0.5 h, 45 minutes = 0.75 h, 20 minutes ≈ 0.33 h.
How do I calculate hours worked overnight?
Enter the end time as it reads on the clock; when it is earlier than the start, the calculator adds a day. 22:00 to 6:00 is 8 hours.
How do I add up a week of hours?
Convert each day to decimal hours and add them: 7.5 + 8 + 7.75 + 8 + 6.5 = 37.75 hours, or 37 h 45.