How to calculate hours between two times
The method is simple: convert each time to minutes since midnight, subtract, and convert back. For 8:15 AM to 4:45 PM: 8:15 AM is 495 minutes, 4:45 PM is 1,005 minutes, so the difference is 510 minutes = 8 hours 30 minutes = 8.5 decimal hours. If the end time is "earlier" than the start (a night shift like 11:00 PM to 7:00 AM), add 24 hours to the end time first — this calculator does that automatically.
Common shift lengths at a glance
| Shift | Raw hours | With 30-min break | With 60-min break |
|---|---|---|---|
| 9:00 AM – 5:00 PM | 8:00 | 7.5 | 7.0 |
| 8:00 AM – 4:30 PM | 8:30 | 8.0 | 7.5 |
| 7:00 AM – 7:00 PM | 12:00 | 11.5 | 11.0 |
| 11:00 PM – 7:00 AM (overnight) | 8:00 | 7.5 | 7.0 |
Minutes to decimal hours
Payroll runs on decimal hours. The conversion is minutes ÷ 60:
| Minutes | 5 | 10 | 15 | 20 | 30 | 40 | 45 | 50 |
|---|---|---|---|---|---|---|---|---|
| Decimal | 0.08 | 0.17 | 0.25 | 0.33 | 0.50 | 0.67 | 0.75 | 0.83 |
Adding up a whole week of shifts? Use the time card calculator — it totals seven days with breaks and overtime.
Frequently asked questions
How many hours is 9 to 5?
8 hours raw. With a 30-minute unpaid lunch, 7.5 paid hours; with an hour lunch, 7 paid hours.
Does this handle overnight shifts?
Yes. If the end time is before the start time, the calculator assumes the shift crossed midnight — 10:00 PM to 6:00 AM = 8 hours.
Why do I need decimal hours?
Multiplying pay is easier with decimals: 7.75 hours × $18 is one multiplication. Timesheets and payroll software almost always use decimal format.