How to calculate work hours with lunch breaks
For a completed shift, subtract unpaid lunch from the clock span. When planning a clock-out time, add unpaid lunch to your required working duration. The direction depends on which answer you need.
1. Find hours worked after lunch
Suppose you start at 8:10 AM, finish at 4:55 PM and take a 45-minute unpaid lunch. The clock span is 8 hours 45 minutes. After subtracting lunch, your working time is 8 hours.
Hours worked = clock span − unpaid breaks 8h 45m − 45m = 8h 00m
Calculate hours worked with breaks
Use minutes for subtraction: 525 elapsed minutes − 45 break minutes = 480 worked minutes. Divide by 60 after subtracting, not before.
2. Find when to clock out
If you need to work 8 hours, a 45-minute unpaid lunch makes the total clock span 8 hours 45 minutes. Starting at 8:10 AM gives a planned finish of 4:55 PM.
Clock-out time = start time + required working time + unpaid breaks 8:10 AM + 8h + 45m = 4:55 PM
The clock-out calculator with lunch break calculates this finish time, including a next-day label when needed.
How different lunch lengths affect an 8-hour day
| Unpaid lunch | Work time if you leave at 5:00 PM | Leave time to complete 8 hours of work |
|---|---|---|
| 0 min | 8h 00m | 5:00 PM |
| 30 min | 7h 30m | 5:30 PM |
| 45 min | 7h 15m | 5:45 PM |
| 60 min | 7h 00m | 6:00 PM |
A “9-to-5 day” describes eight elapsed hours. It only equals eight worked hours in this arithmetic when no unpaid time is deducted.
Choose one way to record the same lunch
For a day from 9:00 AM to 5:00 PM with lunch from 12:30 PM to 1:00 PM, either method gives 7 hours 30 minutes:
- One period: enter 9:00 AM–5:00 PM and 30 unpaid break minutes.
- Two periods: enter 9:00 AM–12:30 PM and 1:00 PM–5:00 PM, with zero additional break minutes.
Using two periods and also deducting that same 30-minute lunch would reduce the result to 7 hours. An additional unpaid break inside either period can still be deducted separately.
Add a week with different break lengths
Imagine five 9:00 AM–5:30 PM days. Each spans 8 hours 30 minutes, so the full clock span is 42 hours 30 minutes. Unpaid breaks of 30, 45, 30, 60 and 30 minutes total 195 minutes, or 3 hours 15 minutes.
42h 30m − 3h 15m = 39h 15m worked 39 + 15 ÷ 60 = 39.25 decimal hours
Enter each day's break in the weekly time card calculator rather than assuming the same deduction every day. For records on paper, use a printable timesheet.
What if lunch is paid, or there are several breaks?
The calculator's break field means “minutes to subtract.” If a break counts toward the working time you are recording, leave it out of that field. The tool does not determine whether a particular break should be paid; use the treatment in your work records.
For several unpaid breaks within one continuous clock span, add their minutes first. A 30-minute lunch plus a separate 15-minute unpaid break becomes 45 minutes. If a shift crosses midnight, follow the overnight-shift example before subtracting the breaks.
When the total needs decimal hours, use the decimal hours converter. For example, 7 hours 45 minutes is 7.75, not 7.45.
Prepared by HourSprout · Updated September 15, 2026. See our calculation methodology.