How to Calculate Hours Worked

The Basic Formula

For each workday, hours worked are the end time minus the start time, minus any unpaid break. Add the days together for the week. Working on a 24-hour clock avoids AM/PM mistakes: 8:00 AM is 08:00 and 5:00 PM is 17:00, so the shift is 9 hours before breaks.

If a shift ends after midnight, add 24 hours to the end time before subtracting: 22:00 to 06:00 is 30:00 − 22:00 = 8 hours.

Which Breaks Count as Work Time

Federal law does not require employers to give breaks, but the U.S. Department of Labor says that when they do, short rest breaks of about 5 to 20 minutes count as hours worked and must be paid (29 CFR 785.18). Bona fide meal periods, usually 30 minutes or more, do not count as work time if you are completely relieved of duty (29 CFR 785.19). So subtract the unpaid lunch, not the coffee breaks. Many states have their own break rules, so check your state labor department too.

Converting to Decimal Hours

Payroll uses decimal hours. Divide leftover minutes by 60: 7 hours 45 minutes is 7.75 hours, and 8 hours 20 minutes is about 8.33 hours. Federal rules allow employers to round clock times to the nearest 5 minutes, tenth of an hour or quarter hour, as long as the rounding averages out so employees are fully paid over time (29 CFR 785.48).

Overtime Under the FLSA

Under the Fair Labor Standards Act, non-exempt employees must receive at least 1.5 times their regular rate for every hour over 40 in a workweek. The Department of Labor defines a workweek as a fixed, regularly recurring period of 168 hours, seven consecutive 24-hour periods, and each workweek stands alone: you cannot average 30 hours one week and 50 the next to avoid overtime. The federal minimum wage is $7.25 an hour, though many states and cities set it higher.

Some states go further. California, for example, generally requires overtime for hours over 8 in a single workday under Labor Code Section 510, so a 10-hour day can earn overtime even in a 40-hour week.

Tips for Accurate Timesheets

• Record times as they happen, not from memory at the end of the week.
• Separate paid and unpaid breaks so you subtract only the unpaid ones.
• Know your workweek start day, since overtime is counted per workweek.
• Exempt or not? Salaried exempt employees are not owed FLSA overtime; check your classification with HR.

Frequently Asked Questions

How do I calculate hours worked in a day?

Subtract your start time from your end time on a 24-hour clock, then subtract unpaid breaks. 8:00 to 17:00 with a 30-minute lunch is 8.5 hours.

Are breaks paid?

Under federal rules, short breaks of about 5 to 20 minutes are paid work time. Meal periods of usually 30 minutes or more can be unpaid if you are fully relieved of duty.

When do I get overtime?

Under the FLSA, non-exempt employees earn at least 1.5 times their regular rate for hours over 40 in a workweek. Some states, such as California, also have daily overtime.

How do I convert minutes to decimal hours for payroll?

Divide the minutes by 60. 45 minutes is 0.75 hours, so 7 hours 45 minutes is 7.75 hours.

Sources

• U.S. Department of Labor, Wage and Hour Division, Fact Sheet #23: Overtime Pay Requirements of the FLSA (dol.gov), 40-hour workweek and 1.5× rate.
• U.S. Department of Labor, "Breaks and Meal Periods" (dol.gov/general/topic/workhours/breaks), and 29 CFR 785.18–785.19.
• 29 CFR 785.48, rounding of recorded time (ecfr.gov).
• U.S. Department of Labor, "Minimum Wage" (dol.gov/general/topic/wages/minimumwage), $7.25 federal minimum.
• California Labor Code Section 510 (leginfo.legislature.ca.gov), daily overtime.

This guide is for education. For tax, payroll or legal decisions, check the rules that apply to you.