How to subtract a lunch break
First calculate the elapsed time from clock-in to clock-out. Then subtract the off-duty meal period. From 8:00 AM to 4:30 PM is 8.5 elapsed hours; subtracting a 30-minute unpaid lunch produces 8.0 worked hours.
Keep the break as a separate field instead of silently changing the clock-out time. That makes the record easier to review and helps distinguish elapsed time from compensable time.
Paid rest breaks and off-duty meals are different
Federal guidance generally treats short rest periods as compensable time. A bona fide meal period is different: the employee must be completely relieved from duty for the purpose of eating a regular meal.
A desk lunch interrupted by calls, customer service, monitoring equipment, or other job duties may not be an uninterrupted off-duty meal. Do not automatically deduct a scheduled lunch when the employee actually worked through it.
- Record actual start, end, and break duration.
- Do not subtract paid rest periods as unpaid time.
- Correct automatic deductions when work interrupted the meal.
- Check state rules for timing, duration, waivers, and premiums.
- Retain the employee’s correction and approval trail.
State rules can add requirements
The federal FLSA does not itself require employers to provide meal or rest periods, but states may require them. California, for example, publishes detailed meal-period guidance and additional remedies can apply.
Use the regional overtime pages as an initial reference and confirm the current rule with the applicable labor agency. This calculator provides arithmetic, not a determination of legal compliance.