How to use the hours calculator
- Enter the start time of the shift.
- Enter the end time. If it's earlier than the start, such as 10:00 PM to 6:00 AM, the calculator treats it as the next morning.
- Enter the unpaid break in minutes, or 0 if there wasn't one.
- Optionally enter the number of shifts like this to get a weekly total.
- Read the hours worked as decimal hours and as hours:minutes.
How hours worked are calculated
Both times are turned into minutes after midnight. For an overnight shift the end time is on the next day, so 24 hours (1,440 minutes) are added before subtracting. A paid break, such as a short rest break that your employer pays for, should not be entered: it counts as time worked.
Worked example
The calculator's defaults are a shift from 9:00 AM to 5:30 PM with a 30-minute unpaid break, worked 5 times:
- Start: 9 × 60 = 540 minutes after midnight. End: 17 × 60 + 30 = 1,050 minutes.
- Shift length: 1,050 − 540 = 510 minutes, or 8 h 30 min.
- Minus the break: 510 − 30 = 480 minutes.
- Decimal hours: 480 ÷ 60 = 8.00 hours, or 8:00 in hours and minutes.
- Five shifts: 8.00 × 5 = 40.00 hours for the week.
For a night shift from 10:00 PM to 6:15 AM with a 45-minute break: 6:15 AM is 375 minutes, plus 1,440 for the next day is 1,815; minus 1,320 for 10:00 PM gives 495 minutes. Take off 45 and you get 450 minutes, which is 7.50 hours.
Hours and minutes vs. decimal hours
A time like 7:45 means 7 hours and 45 minutes, which is 7.75 hours, not 7.45. Payroll and invoicing systems almost always want the decimal figure, because it multiplies cleanly by an hourly rate: 7.75 hours at $20 an hour is $155.
| Hours:minutes | Decimal | Hours:minutes | Decimal |
|---|---|---|---|
| 0:15 | 0.25 | 7:30 | 7.50 |
| 0:20 | 0.33 | 7:45 | 7.75 |
| 0:30 | 0.50 | 8:00 | 8.00 |
| 0:40 | 0.67 | 8:20 | 8.33 |
| 0:45 | 0.75 | 8:50 | 8.83 |
Some employers round clock-in and clock-out times to the nearest 5, 6 or 15 minutes. U.S. federal rules (29 CFR 785.48) accept this only if, over time, it doesn't leave employees underpaid for the time they actually worked. If your pay slip shows fewer hours than this calculator, rounding is one possible reason worth asking about.
Tracking a whole week
For a week with different times each day, use the time card calculator. It adds up each day, separates regular hours from overtime and works out your pay. For adding or subtracting hours from a clock time, try the time calculator.
Frequently asked questions
How do I calculate hours worked overnight?
Add 24 hours to the end time before subtracting the start. A shift from 10:00 PM to 6:00 AM is (6 + 24) − 22 = 8 hours. The calculator does this automatically whenever the end time is earlier than the start time.
How do I convert minutes to decimal hours?
Divide the minutes by 60. 45 minutes is 45 ÷ 60 = 0.75 hours, and 20 minutes is 0.33 hours. Add the result to the whole hours, so 6 hours 20 minutes is 6.33 hours.
Should I include my lunch break?
Enter only breaks that you're not paid for, which is usually a meal break of 30 minutes or more. Short rest breaks are usually paid, and under U.S. federal rules breaks of 5 to 20 minutes count as hours worked, so leave them in.
What if my shift is longer than 24 hours?
The calculator handles shifts up to 24 hours, measured from a start time to an end time on the clock. For longer stretches, enter the start and end dates and times in the time duration calculator.
Related calculators
- Time Card Calculator — Weekly time sheet for Monday to Sunday with breaks, overtime after 40 hours and total pay at your hourly rate.
- Time Calculator — Add or subtract days, hours, minutes and seconds from a time, combine two durations, or convert between time units.
- Time Duration Calculator — The exact time between two dates and times, in days, hours and minutes, with totals in every unit.
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