To calculate work hours, find the elapsed time between the clock-in and clock-out times, then subtract unpaid or excluded breaks. For example, a shift from 9:00 AM to 5:30 PM lasts 8 hours 30 minutes. After subtracting a 30-minute lunch break, the counted work time is eight hours.
Calculate elapsed hours and minutes, overnight duration, break deductions, decimal hours, total minutes, and seconds.
Paid breaks remain included, while unpaid breaks are commonly removed from counted work hours.
Work-Hours Formula
Calculate the complete elapsed shift before deducting excluded breaks.
Convert all values into minutes when the hours and minutes differ.
The Time Duration Calculator includes separate break-hour and break-minute fields.
Example: 9:00 AM to 5:30 PM with a 30-Minute Break
The complete elapsed shift is 8 hours 30 minutes.
Convert this to 510 minutes.
Subtract the 30-minute break to obtain 480 minutes, equal to eight hours.
Step 1: Calculate the Elapsed Shift
Subtract the clock-in time from the clock-out time.
Account for midnight when the shift continues into the following day.
Do not subtract breaks until the complete shift duration has been found.
Step 2: Add the Excluded Breaks
Combine lunch and any other unpaid breaks.
For example, a 30-minute lunch and a 15-minute unpaid break total 45 minutes.
Paid breaks should remain included unless the calculation requires otherwise.
Step 3: Subtract the Break Total
Subtract the combined excluded break duration from the elapsed shift.
A nine-hour elapsed shift with one hour of unpaid breaks leaves eight worked hours.
The excluded break cannot be longer than the elapsed shift.
Example with Multiple Breaks
A shift from 8:00 AM to 5:00 PM lasts nine hours.
A 30-minute lunch and two 15-minute unpaid breaks total one hour.
The counted work time is eight hours.
Only subtract breaks that should be excluded from the recorded work duration.
Overnight Work Shifts
Treat the clock-out time as occurring on the following day.
A shift from 10:00 PM to 6:00 AM lasts eight hours.
After a 30-minute unpaid break, the counted duration is 7 hours 30 minutes.
Convert Work Time to Decimal Hours
Divide the remaining minutes by 60.
Seven hours 30 minutes become 7.5 decimal hours.
Seven hours 45 minutes become 7.75 decimal hours.
Example: 8:30 AM to 5:15 PM with a 45-Minute Break
The elapsed shift is 8 hours 45 minutes, equal to 525 minutes.
Subtracting 45 minutes leaves 480 minutes.
The counted duration is eight hours or 8.0 decimal hours.
Daily and Weekly Work Hours
Calculate each day's net work time separately.
Add the daily results to find the weekly total.
Using minutes or decimal hours prevents errors when days contain different minute values.
Overtime Calculations
Find the complete counted work duration before separating standard and overtime hours.
The definition of overtime depends on the applicable employment rules or agreement.
Keep accurate daily records when thresholds are based on daily as well as weekly hours.
Common Shift Examples
The following examples show elapsed and break-adjusted work time.
| Clock-in and clock-out | Break | Counted work time |
|---|---|---|
| 9:00 AM–5:30 PM | 30m | 8h |
| 8:00 AM–5:00 PM | 1h | 8h |
| 8:30 AM–5:15 PM | 45m | 8h |
| 10:00 PM–6:00 AM | 30m | 7h 30m |
| 7:45 AM–4:30 PM | 30m | 8h 15m |
Common Mistakes
Do not subtract paid breaks unless they should be excluded.
Do not forget to account for an overnight clock-out time.
Do not write 7 hours 30 minutes as 7.30 decimal hours.
Calculate daily net hours before adding a weekly total.
Conclusion
Calculate the complete shift duration and subtract only unpaid or excluded breaks.
Convert the net result into decimal hours when required for payroll or reporting.
Use the Time Duration Calculator to calculate break-adjusted same-day and overnight work time.
FAQs
How do I calculate work hours with a break?
Calculate the elapsed shift and subtract unpaid or excluded break time.
How many work hours are there from 9:00 AM to 5:30 PM with a 30-minute break?
The counted work duration is eight hours.
Should paid breaks be subtracted?
Normally, only breaks excluded from counted work time should be subtracted.
How do I calculate an overnight shift?
Treat the clock-out time as occurring on the following day.
How do I convert work time into decimal hours?
Divide the net work minutes by 60.