How to calculate hours worked, breaks and overtime

To calculate hours worked, subtract the start time from the end time, then subtract any unpaid meal break. Convert the leftover minutes to a decimal by dividing by 60, so 7 hours 45 minutes is 7.75 hours, not 7.45. Add up the days in the workweek. Under federal law, nonexempt employees must be paid at least 1.5 times their regular rate for every hour over 40 in a workweek.

That covers most timesheets. The details below cover the parts that trip people up: borrowing minutes, which breaks count, shifts that cross midnight, daylight saving time, overtime and rounding. Each part has an example worked exactly.

The basic method, step by step

1. Write both times in 24-hour format. 5:23 p.m. becomes 17:23. This removes a.m./p.m. mistakes.
2. Subtract start from end. If the end minutes are smaller than the start minutes, borrow 1 hour as 60 minutes.
3. Subtract unpaid breaks, which are usually meal periods (see below for which breaks count).
4. Convert minutes to a decimal by dividing by 60, if you need decimal hours for payroll.

Hours worked = (end time − start time) − unpaid breaks Decimal hours = whole hours + (minutes ÷ 60)

Example 1: one day with a lunch break

You clock in at 8:47 a.m., clock out at 5:23 p.m., and take a 30-minute unpaid lunch.

5:23 p.m. → 17:23 17:23 − 8:47: 23 minutes is less than 47, so borrow an hour → 16:83 − 8:47 = 8 hours 36 minutes Minus 30-minute lunch → 8 hours 6 minutes Decimal: 8 + 6 ÷ 60 = 8 + 0.1 = 8.1 hours

The hours calculator does this for each day of the week and shows the same working.

Converting minutes to decimal hours

Payroll systems multiply decimal hours by an hourly rate, so 7:45 on a timesheet has to become 7.75 before it's multiplied. Writing it as “7.45” is the most common timesheet error. At $20 an hour it underpays by 0.30 × $20 = $6 a day, or $30 over a five-day week.

Multiples of 6 minutes convert to exact tenths of an hour, and multiples of 15 minutes to exact quarters. Most other values repeat forever. That's why it's safest to total minutes first and divide by 60 once, at the end. The hours to minutes converter goes the other way.

Adding up a week (with overtime)

Example 2: a five-day timesheet at $18.60 an hour

Total minutes: 493 + 525 + 488 + 570 + 454 = 2,530 min = 42 h 10 min Regular pay: 40 h × $18.60 = $744.00 Overtime rate: 1.5 × $18.60 = $27.90/h Overtime hours: 2 h 10 min = 2⅙ h Overtime pay: 2⅙ × $27.90 = $60.45 Total pay: $744.00 + $60.45 = $804.45

If the overtime hours had been rounded to 2.17 first, the result would be 2.17 × $27.90 = $60.54. That's 9 cents off from rounding alone. Keep hours and minutes, or exact fractions, until the final multiplication. A percentage calculator and our guide to everyday percentages help with checking raises and deductions on the same paycheck.

Which breaks count as hours worked

Federal law doesn't require employers to give lunch or coffee breaks. When breaks are given, the U.S. Department of Labor applies these rules under the FLSA:

• Short breaks (usually 5 to 20 minutes) are paid. They count as hours worked, including when working out overtime.
• Bona fide meal periods (typically 30 minutes or more) are not work time, but only if you're completely relieved from duty. The DOL's own example: an employee who eats at their desk while regularly answering the phone is working, and that time must be paid.

Some states require meal or rest breaks, or set their own rules for them. The Department of Labor keeps state-by-state tables for meal periods and paid rest periods.

Overnight shifts and daylight saving time

Example 3: a shift that crosses midnight

A night shift runs from 10:00 p.m. to 6:30 a.m. with a 30-minute unpaid meal break.

End time is earlier than start time, so add 24 hours to the end: 6:30 + 24:00 = 30:30 30:30 − 22:00 = 8 hours 30 minutes Minus 30-minute meal → 8 hours 0 minutes = 8.0 hours

Twice a year the clock time and the real time don't match. US daylight saving time ends on the first Sunday in November. At 2:00 a.m. clocks go back to 1:00 a.m., so the same 10:00 p.m.–6:30 a.m. shift actually lasts 9 hours of work after the break. DST starts on the second Sunday in March, when clocks jump from 2:00 to 3:00 a.m. That night the shift lasts 7 hours. Pay is owed for time actually worked, so check how your time clock records those two nights.

Also note which workweek a shift falls in. Under the FLSA a workweek is a fixed, regularly recurring 168-hour period. It can start on any day and at any hour your employer sets, not necessarily Sunday at midnight. For multi-week date ranges, the days between dates calculator helps.

Federal overtime basics (FLSA)

• The rule: covered, nonexempt employees get at least 1.5 times their regular rate for hours over 40 in a workweek.
• Weekly, not daily: the FLSA doesn't require overtime for hours over 8 in a day. It also doesn't require overtime for weekends or holidays as such.
• No averaging: each workweek stands alone. Hours can't be averaged across two or more weeks, even when you're paid every two weeks.
• The regular rate isn't always your base wage. For workers paid by piece rate, salary, commission or other methods, the regular rate is total pay for the week divided by hours worked, with some statutory exclusions. Some bonuses can raise it. See DOL Fact Sheet #56A.
• Not everyone is covered. Some salaried employees are exempt from overtime. The rules depend on duties and pay, so check the DOL's overtime pages.

Here's why averaging matters. Someone earning $18.60 an hour who works 45 hours one week and 35 the next has 80 hours in the pay period, but not 80 regular hours. Week 1 pays 40 × $18.60 + 5 × $27.90 = $883.50. Week 2 pays 35 × $18.60 = $651.00. The total is $1,534.50, which is $46.50 more than paying 80 hours at straight time ($1,488.00).

State rules vary. Some states have their own overtime laws, including daily overtime in some cases, and many set a higher minimum wage. The DOL says that when an employee is covered by both state and federal overtime laws, the employee gets overtime under the higher standard. Your state labor office is the authority for your state.

Time clock rounding

Many time clocks round punches to the nearest 5 minutes, tenth of an hour (6 minutes) or quarter hour. Federal regulations (29 CFR 785.48) accept this for enforcement only if it averages out over time and employees are paid for all the time they actually work. The math of “nearest quarter hour” means a punch 1–7 minutes past the quarter rounds down, and 8–14 minutes past rounds up. So 8:07 records as 8:00 and 8:08 as 8:15. If the rounding always seems to go against you, add up your actual punches for a few weeks and compare.

Common timesheet mistakes

• Writing minutes as decimals (7:45 as 7.45 instead of 7.75).
• Mixing up a.m. and p.m. Convert to 24-hour time first.
• Deducting a break you worked through. A meal period only comes off if you were fully relieved from duty.
• Rounding each day to two decimals before adding. Total the minutes, then convert once.
• Averaging overtime across a two-week pay period. Overtime is worked out one workweek at a time.

To turn your hourly total into weekly, monthly or annual pay, use the salary calculator. For timing tasks as you go, the stopwatch works in any browser. This guide explains federal basics only and isn't legal advice. For a pay dispute, contact the DOL's Wage and Hour Division or your state labor office.