How to Calculate Hours Worked from Start and End Time

To calculate hours worked, subtract the start time from the end time, then subtract unpaid break time. A 9:00 AM to 5:30 PM shift is 8 hours 30 minutes. If lunch is 30 unpaid minutes, paid time is 8 hours. The Hours Calculator handles one shift, and the Time Card Calculator totals the full week.

Only subtract a break when it is unpaid and the worker is fully relieved from duty. A 30-minute unpaid lunch comes out of the total; a paid rest break stays in. If you are not sure how much unpaid time is costing you across a week, the Unpaid Break Calculator totals the hours and dollars.

When a shift crosses midnight, count forward into the next day instead of subtracting the clock numbers directly. For example, 10:00 PM to 6:00 AM is 8 hours, not negative 16. The Hours Calculator has an overnight option so the result does not flip backward.

For payroll, calculate each shift first and then add the week. Five shifts of 8 hours is 40 hours; a sixth 6-hour shift makes 46 hours, which may create overtime. Use the Time Card Calculator when you have clock-in and clock-out times, or the Add Time Calculator when you already have daily totals.