How to calculate hours between two times
- Write both times in 24-hour format: 8:45 AM is 8:45, 5:15 PM is 17:15.
- Subtract the start time from the end time. Borrow 60 minutes from the hours if the minutes go negative.
- If the result is negative, the time range crosses midnight: add 24 hours.
- Subtract any unpaid break.
- For payroll, convert to decimal hours: divide the minutes by 60.
Decimal hours = Hours + Minutes ÷ 60
Example
A shift from 8:45 AM to 5:15 PM: 17:15 − 8:45 = 8 hours 30 minutes. 30 ÷ 60 = 0.5, so that is 8.5 hours. With a 30-minute unpaid lunch, 8 hours of paid time.
Overnight example
10:30 PM to 6:15 AM: 6:15 − 22:30 = −16:15. Add 24 hours: 7 hours 45 minutes, or 7.75 hours.
Hours between common times
| From | To | Hours : minutes | Decimal hours | With 30 min break |
|---|---|---|---|---|
| 9:00 AM | 5:00 PM | 8:00 | 8.00 | 7.50 |
| 8:00 AM | 5:00 PM | 9:00 | 9.00 | 8.50 |
| 8:00 AM | 4:30 PM | 8:30 | 8.50 | 8.00 |
| 9:00 AM | 6:00 PM | 9:00 | 9.00 | 8.50 |
| 7:00 AM | 3:30 PM | 8:30 | 8.50 | 8.00 |
| 7:00 AM | 3:00 PM | 8:00 | 8.00 | 7.50 |
| 6:00 AM | 2:00 PM | 8:00 | 8.00 | 7.50 |
| 8:00 AM | 12:00 PM | 4:00 | 4.00 | 3.50 |
| 12:00 PM | 8:00 PM | 8:00 | 8.00 | 7.50 |
| 10:00 AM | 7:00 PM | 9:00 | 9.00 | 8.50 |
| 7:00 AM | 7:00 PM | 12:00 | 12.00 | 11.50 |
| 7:00 PM | 7:00 AM (next day) | 12:00 | 12.00 | 11.50 |
| 10:00 PM | 6:00 AM (next day) | 8:00 | 8.00 | 7.50 |
| 11:00 PM | 7:00 AM (next day) | 8:00 | 8.00 | 7.50 |
| 3:00 PM | 11:00 PM | 8:00 | 8.00 | 7.50 |
Minutes to decimal hours
Payroll and invoices use decimal hours. Divide minutes by 60 and round to two decimal places:
| Minutes | Decimal | Minutes | Decimal |
|---|---|---|---|
| 5 min | 0.08 | 35 min | 0.58 |
| 10 min | 0.17 | 40 min | 0.67 |
| 15 min | 0.25 | 45 min | 0.75 |
| 20 min | 0.33 | 50 min | 0.83 |
| 25 min | 0.42 | 55 min | 0.92 |
| 30 min | 0.50 | 60 min | 1.00 |
Hours calculator questions
How do I calculate hours between two times?
Write both times in 24-hour format and subtract the start from the end. If the result is negative, the shift ends the next day, so add 24 hours. Then divide the minutes by 60 to get decimal hours. Example: 8:45 AM to 5:15 PM is 17:15 − 8:45 = 8 hours 30 minutes, or 8.5 hours.
How many hours is 9 to 5?
9 AM to 5 PM is 8 hours. With an unpaid 30-minute lunch break it is 7.5 hours of paid work, or 37.5 hours over a five-day week.
How do I count hours for a shift that ends after midnight?
Count the hours up to midnight and add the hours after it. 10 PM to 6 AM is 2 hours before midnight plus 6 after, 8 hours in total. The calculator does this automatically when the end time is earlier than the start time.
Is 8 hours 30 minutes the same as 8.30 hours?
No. 8 hours 30 minutes is 8.5 decimal hours, because 30 minutes is half an hour. 8.30 decimal hours is 8 hours 18 minutes. Payroll systems use decimal hours, so convert minutes by dividing them by 60.
How many hours is 7 AM to 7 PM?
7 AM to 7 PM is 12 hours, and so is 7 PM to 7 AM. Three 12-hour shifts make a 36-hour week.
How many work hours are in a year?
A full-time schedule of 40 hours a week for 52 weeks is 2,080 hours a year. That is the number used to convert an annual salary to an hourly rate.