How to use the Hours Calculator
- Enter a start time and an end time.
- Add an unpaid break in minutes, or leave it at 0.
- Read the time worked in hours and minutes, decimal hours and total minutes.
How it works
The calculator turns both times into minutes after midnight, subtracts the start from the end and removes the break. When the end time is earlier than the start time, it assumes the period crosses midnight and adds 24 hours.
Decimal hours are the hours plus the minutes divided by 60. Timesheets and payroll software often ask for decimal hours, so 6 hours 20 minutes becomes 6.33.
Formula
Minutes = end − start − break (add 1,440 if end is before start) Decimal hours = minutes ÷ 60
Example
From 8:45 AM to 5:15 PM is 8 hours 30 minutes. Take off a 30-minute lunch and the time worked is 8h 00m, or 8.00 decimal hours.
Common time calculations
| Shift | Break | Time worked | Decimal |
|---|---|---|---|
| 9:00 AM – 5:00 PM | 30 min | 7h 30m | 7.50 |
| 8:00 AM – 4:30 PM | 30 min | 8h 00m | 8.00 |
| 7:00 AM – 3:30 PM | 45 min | 7h 45m | 7.75 |
| 12:00 PM – 8:20 PM | none | 8h 20m | 8.33 |
| 10:00 PM – 6:00 AM | 30 min | 7h 30m | 7.50 |
Breaks are often unpaid, but rules vary. In the US federal law does not require meal breaks, though several states do. In Canada, Australia, the UK and the Netherlands workers are entitled to rest breaks after a set number of hours. Check your contract or local labour rules to see whether a break should be paid.
Frequently asked questions
How many hours is 9 to 5?
8 hours. With a 30-minute unpaid lunch it is 7.5 hours, and with a 1-hour lunch it is 7 hours.
How do I calculate hours across midnight?
Count from the start time to midnight, then add the time from midnight to the end. 10:00 PM to 6:00 AM is 2 hours plus 6 hours, or 8 hours. The calculator does this for you.
What is 8 hours 20 minutes as a decimal?
8.33 hours, because 20 ÷ 60 = 0.333.
Should I use this or the time card calculator?
Use this page for one period of time. For a whole week with overtime and pay, use the time card calculator.
Last reviewed October 20, 2026. Spotted an error? Tell us.