How to Calculate Hours Worked

Hours worked = elapsed shift time - unpaid breaks. Convert the start and end times to a duration, then subtract any unpaid break time.

The hours worked formula

Hours worked = elapsed shift time - unpaid breaks

Only subtract breaks that are unpaid. If a shift crosses midnight, treat the end time as belonging to the next day.

Worked examples

Example 1: A full workday

Start at 8:00 AM and finish at 5:00 PM. The gross shift is 9 hours. Subtract a 1-hour unpaid lunch to get 8 hours worked.

Example 2: Minutes and decimal hours

Start at 8:30 AM and finish at 5:15 PM. The gross shift is 8 hours 45 minutes. Subtract a 30-minute unpaid break to get 8 hours 15 minutes.

Convert 15 minutes to a fraction of an hour: 15 / 60 = 0.25. The result is 8.25 decimal hours.

Example 3: An overnight shift

A shift from 10:00 PM to 6:00 AM crosses midnight. That is 8 hours before breaks. Subtract a 30-minute unpaid break to get 7 hours 30 minutes worked.

If the end time is earlier than the start time, the shift usually crosses midnight. Count 2 hours to midnight and another 6 hours to 6:00 AM. This assumes no clock change during the shift; if a clock changes, account for the actual elapsed time separately.

How to calculate a shift by hand

Write down the start time and end time.
Convert each clock time to minutes after midnight. When the shift ends the next day, add 1,440 minutes to the end time before subtracting the start time.
Subtract the total unpaid break time.
Convert the remaining minutes to decimal hours by dividing by 60.

For a single shift with an unpaid break, calculate your work hours with the Work Hours Calculator. For a weekly total, use the Time Card Calculator.

When you already know the hours and minutes, use the Decimal Hours Calculator to convert the duration. The minutes-to-decimal-hours guide explains the conversion and rounding.

If you have several unpaid breaks, add their durations before subtracting them. The Break Time Calculator can keep paid and unpaid totals separate.

For split work periods, calculate each period and add the worked time. Use the Shift Hours Calculator to total those periods without counting the gaps between them.