How to Calculate Work Hours
A reliable work-hours calculation starts with elapsed minutes, subtracts only unpaid breaks, and converts the final duration for display or payroll use.
The basic work-hours formula
Worked time = clock-out time − clock-in time − unpaid breaks. Perform the subtraction in minutes to avoid mixing clock notation with decimal numbers.
Step-by-step method
- Convert clock-in and clock-out to minutes after midnight.
- If an allowed shift ends after midnight, add 1,440 minutes to the clock-out value.
- Subtract clock-in from clock-out to find elapsed time.
- Subtract unpaid break minutes.
- Convert the net minutes to hours and minutes or divide by 60 for decimal hours.
Worked example
8:30 AM is 510 minutes and 5:00 PM is 1,020 minutes. The elapsed shift is 510 minutes. After a 30-minute unpaid break, worked time is 480 minutes: 8 hours or 8.00 decimal hours.
Common mistakes
Do not treat 8 hours 30 minutes as 8.30 decimal hours; it is 8.50. Do not deduct a paid break, and do not treat an earlier clock-out as overnight unless the shift is allowed to cross midnight.
Check a shift with the Work Hours Calculator.