Hours calculator
This hours calculator finds how long you worked between a start and end time, takes off your unpaid lunch break, and gives the answer in hours and minutes and in decimal hours for payroll.
- Works for overnight shifts
- Takes off an unpaid break
- Optional rounding and pay
Last updated
How to use the hours calculator
- Enter the time you started and the time you finished. If you finished after midnight, just enter the end time; the calculator adds the extra day.
- Enter your unpaid break in minutes, such as 30 for a half-hour lunch. Leave it at 0 if your breaks were paid.
- Pick a rounding rule only if your employer rounds clock punches, then add your hourly rate if you want to see the pay.
- Read the hours as h:mm, or copy the decimal hours onto a timesheet.
How to calculate hours worked
Turn both clock times into minutes after midnight, subtract the start from the end, then take off the unpaid break. If the end time is earlier than the start, the shift ran past midnight, so add 24 hours (1,440 minutes) first.
hours worked = (end − start) − unpaid break
To get decimal hours, divide the minutes by 60. 8 hours 30 minutes is 8 + 30 ÷ 60 = 8.5 hours. Payroll multiplies the decimal hours by the hourly rate.
Worked example
A night shift runs from 10:00 PM to 6:30 AM with a 30-minute unpaid meal break.
- In 24-hour time the shift starts at 22:00 and ends at 6:30. The end is earlier than the start, so add 24 hours: 6:30 becomes 30:30.
- Subtract: 30:30 − 22:00 = 8 hours 30 minutes.
- Take off the break: 8:30 − 0:30 = 8 hours 0 minutes.
- In decimal that is 8.00 hours. At $18.50 an hour, the pay is 8 × $18.50 = $148.00.
Enter 22:00, 06:30, a 30-minute break and a rate of 18.50 in the calculator and it shows the same 8:00 and $148.00.
Common shifts and their hours
These are worked hours after the unpaid break, in hours and minutes and in decimal.
| Shift | Unpaid break | Hours (h:mm) | Decimal |
|---|---|---|---|
| 9:00 AM to 5:00 PM | 30 min | 7:30 | 7.50 |
| 9:00 AM to 5:30 PM | 30 min | 8:00 | 8.00 |
| 8:00 AM to 5:00 PM | 60 min | 8:00 | 8.00 |
| 7:00 AM to 3:30 PM | 30 min | 8:00 | 8.00 |
| 7:00 AM to 7:00 PM | 30 min | 11:30 | 11.50 |
| 10:00 PM to 6:30 AM | 30 min | 8:00 | 8.00 |
| 11:00 PM to 7:00 AM | None | 8:00 | 8.00 |
Breaks and rounding: what counts as work time
Under the federal Fair Labor Standards Act, short rest breaks (usually 20 minutes or less) count as hours worked and must be paid. A meal period, usually 30 minutes or more, can be unpaid only if you are fully relieved of duty. That is why this calculator asks for the unpaid break only.
Some employers round clock punches. Federal rules accept rounding to the nearest 5 minutes, tenth of an hour (6 minutes) or quarter hour (15 minutes), as long as over time it does not shortchange workers. With 15-minute rounding, a punch at 8:07 counts as 8:00 and a punch at 8:08 counts as 8:15. State rules can be stricter.
Common questions
How do I calculate my hours worked?
Subtract your start time from your end time, then take off any unpaid break. 8:30 AM to 5:00 PM is 8 hours 30 minutes; minus a 30-minute lunch, that is 8 hours.
How do I calculate hours for an overnight shift?
Add 24 hours to the end time, then subtract the start time. 11:00 PM to 7:00 AM becomes 31:00 minus 23:00, which is 8 hours.
How do I convert hours and minutes to decimal hours?
Divide the minutes by 60 and add them to the hours. 7 hours 45 minutes is 7 + 45 ÷ 60 = 7.75 hours, and 6 hours 20 minutes is 6.33 hours.
Is a 30-minute lunch break paid?
Under federal law a meal break of about 30 minutes or more can be unpaid if you are completely relieved of duty. Breaks of 20 minutes or less count as work time and are paid. Some states have their own meal break rules.
How many hours is 9 to 5?
9:00 AM to 5:00 PM is 8 hours. With an unpaid 30-minute lunch it is 7.5 hours of paid time, and with a 1-hour lunch it is 7 hours.
How do I add up hours for a whole week?
Find the hours for each day, then add them. The time card calculator does this for seven days at once and shows overtime past 40 hours.
Related calculators
- Time card calculatorTotal a week of start and end times with lunch breaks and overtime pay
- Time calculatorAdd, subtract, multiply or divide hours, minutes and seconds
- Overtime calculatorOvertime and double time pay under federal and state rules
- Military time converterConvert 24-hour military time to 12-hour AM/PM time and back
Sources
- U.S. Department of Labor, Fact Sheet #22: Hours Worked Under the FLSA. Rest breaks of 20 minutes or less are paid; bona fide meal periods can be unpaid
- 29 CFR 785.48, Use of time clocks (rounding). Rounding to the nearest 5 minutes, tenth or quarter hour
See the methodology page for how Clockfigure builds and checks its calculators.