How to Calculate Work Hours

Start with your shift length

To calculate work hours, first find the total time between your start time and end time.

If your shift crosses midnight, treat the end time as happening on the next day.

Subtract unpaid breaks

Once you know the full shift length, subtract any unpaid break time.

For example, if you worked 8.5 hours and had a 30-minute unpaid lunch, your paid time would be 8.0 hours.

Breaks are usually easiest to subtract in minutes. A 15-minute break is 0.25 hours, a 30-minute break is 0.5 hours, and a 45-minute break is 0.75 hours.

Double-check your total

If you work multiple days, repeat the same process for each shift and add the totals together.

This helps you confirm your weekly hours before looking at overtime or paycheck estimates.

When your total is close to 40 hours, check the exact minutes instead of rounding too early. Small rounding differences can change whether part of a shift counts as overtime.

Common time card mistakes

The most common mistakes are forgetting to subtract unpaid lunch, treating an overnight shift as a negative number, or mixing hours and minutes in the same total.

If you write down 7 hours and 30 minutes, convert it to 7.5 hours before adding it to other shifts.