To calculate hours worked, subtract the start time from the end time and take off any unpaid break: 9:00 AM to 5:30 PM with a 30 minute lunch is 8 hours, or 8.00 in decimal. This work hours calculator does it for one shift as you type, including night shifts that run past midnight.
How to use the calculator
- Type the In time, for example 7:45 or 745. On the 12 hour clock, pick AM or PM next to the field, or type it (7:45a, 4:15p).
- Type the Out time. If you leave out AM or PM on the end time, the calculator picks the one that makes the shorter shift: 9 AM to "5" means 5 PM, and 10 PM to "6" means 6 AM the next day.
- Enter the unpaid Break in minutes (30) or hours and minutes (1:00). Leave it empty if you had none.
- Read the result: hours and minutes (8:30) and decimal hours (8.50).
Need the whole week, or two? Switch from Day to Week or 2 weeks at the top, or use the time card calculator for a week of payroll hours.
Worked example: four kinds of shifts
| Shift | In | Out | Break | Hours worked | Decimal |
|---|---|---|---|---|---|
| Office day | 9:00 AM | 5:30 PM | 30 min | 8:00 | 8.00 |
| Odd minutes | 7:45 AM | 4:15 PM | none | 8:30 | 8.50 |
| Long shift | 7:00 AM | 7:00 PM | 30 min | 11:30 | 11.50 |
| Night shift | 10:00 PM | 6:30 AM | 30 min | 8:00 | 8.00 |
The night shift ends the next morning. The calculator marks the Out time with +1 ("Ends the next day") and counts all 8 hours on the day the shift started, so a shift that begins on Friday night stays on Friday.
How to calculate hours between two times by hand
- Write both times on the 24 hour clock. 4:15 PM is 16:15, 10:00 PM is 22:00. AM times stay the same, except 12 AM, which is 0:00.
- Subtract the start from the end. If the minutes of the end time are smaller, borrow an hour: 16:15 minus 7:45 becomes 15:75 minus 7:45, which is 8:30.
- If the end is earlier than the start, the shift crossed midnight. Add 24 hours to the end time first: 6:30 becomes 30:30, and 30:30 minus 22:00 is 8:30.
- Take off the unpaid break: 8:30 minus 30 minutes is 8:00.
- Convert to decimal if you need it: divide the minutes by 60. 30 minutes is 0.5, so 8:30 is 8.5 hours. The hours to decimal converter has a chart for every minute.
Common shift lengths
| Shift | Break | Hours worked | Decimal |
|---|---|---|---|
| 9 AM to 5 PM | none | 8:00 | 8.00 |
| 9 AM to 5 PM | 30 min | 7:30 | 7.50 |
| 8 AM to 5 PM | 1 hour | 8:00 | 8.00 |
| 7 AM to 3:30 PM | 30 min | 8:00 | 8.00 |
| 6 AM to 2:30 PM | 30 min | 8:00 | 8.00 |
| 3 PM to 11:30 PM | 30 min | 8:00 | 8.00 |
| 11 PM to 7 AM | none | 8:00 | 8.00 |
Which breaks to subtract
In the U.S., coffee and snack breaks are rest periods of about 5 to 20 minutes and are paid work time under federal rules (29 CFR 785.18), so a 10 minute coffee break stays in your hours. A bona fide meal period, ordinarily 30 minutes or more, is not work time, but only if you are completely relieved from duty. Eating at your desk while you keep working counts as work time (29 CFR 785.19(a)). Enter in the Break field only a meal break during which you were fully off duty.
In the UK, the calculator uses the 24 hour clock and the UK preset, which flags a day of more than 6 hours with a break under 20 minutes (Working Time Regulations 1998, reg. 12). In the week view it also flags less than 11 hours of rest between two shifts (reg. 10).
This is a calculation, not legal advice.
Shifts past midnight and other edge cases
- Start equals end. 9:00 AM to 9:00 AM counts as 0 hours with a warning, never as 24 hours.
- A real 24 hour shift. Split it at midnight over two days in the Week view: 7:00 AM to 12:00 AM (midnight, with the end set to AM) is 17:00 on the first day, 12:00 AM to 7:00 AM is 7:00 on the second, 24:00 in total.
- A break longer than the shift shows an error instead of negative hours.
- Overtime on a night shift follows the start day too, which matters for daily overtime rules. The overtime calculator has the details per state.
FAQ
How many hours is 9 to 5?
8 hours. With a 30 minute unpaid lunch it is 7.5 hours (7:30), and with a one hour lunch it is 7 hours.
How do I calculate the hours worked between two times?
Subtract the start time from the end time on the 24 hour clock, then subtract the unpaid break. 7:45 AM to 4:15 PM is 16:15 minus 7:45, which is 8 hours 30 minutes.
How do I count a night shift that goes past midnight?
Add 24 hours to the end time before you subtract. 10:00 PM to 6:30 AM is 30:30 minus 22:00, which is 8:30. The calculator does this on its own when the end time is earlier than the start time.
Is a 30 minute lunch counted as hours worked?
Not if you were completely relieved from duty: under federal rules a bona fide meal period is not work time, so subtract it. If you ate at your desk while working, it counts as work time. Short rest breaks of 5 to 20 minutes are paid and stay in your hours.
How many hours is 7 AM to 7 PM?
12 hours. With a 30 minute unpaid break it is 11 hours 30 minutes, or 11.5 in decimal.
What does 8.5 hours mean in hours and minutes?
8 hours 30 minutes. The decimal part is a share of an hour: 0.5 times 60 is 30 minutes, and 0.25 would be 15 minutes.
What if I type the end time without AM or PM?
The calculator picks the AM or PM that gives the shorter shift, which is right for almost every shift. If it guessed wrong, switch AM or PM next to the field.
How do I count a split shift?
Enter the first start and the last end, and type the unpaid gap between the two parts as the break. 10:00 AM to 2:00 PM plus 5:00 PM to 9:00 PM is 10:00 AM to 9:00 PM with a 3:00 break, so 8 hours worked.