How to Calculate Hours Worked
How to calculate hours worked: subtract clock in from clock out, take off unpaid breaks, then add the days. Check examples in the calculator.
In this guide (5 steps)
Step 1 of 5: Read the times
Write each clock in and clock out as hours and minutes. From 9:00 AM to 5:30 PM, count 3 hours to noon, which is 9:00 to 12:00, then 5 hours and 30 minutes after noon. That is 8 hours 30 minutes, or 8:30.
Times that cross noon trip people up. A quick way is to convert PM times to a 24 hour clock by adding 12 to the hour: 5:30 PM becomes 17:30. Then 17:30 minus 9:00 is 8:30. When the minutes of the clock out are smaller than the clock in, borrow an hour. For 7:45 AM to 4:15 PM, that is 16:15 minus 7:45. The 15 minutes is less than 45, so borrow an hour: 15 hours 75 minutes minus 7 hours 45 minutes is 8 hours 30 minutes.
Step 2 of 5: Handle shifts that cross midnight
If the clock out is earlier on the clock than the clock in, the shift ended the next day. Add 24 hours to the clock out before you subtract. 10:00 PM to 6:00 AM is 22:00 to 30:00, which is 8:00.
This is a time calculation only. If you need to know which day those hours belong to for overtime, that depends on how your employer defines the workday and workweek. You can set both on the daily shifts tab of the overtime calculator.
Step 3 of 5: Subtract unpaid breaks
Take off any break that you were not paid for. 8:30 minus a 30 minute lunch is 8:00 of paid time.
Which breaks count as paid is a legal question, not an arithmetic one. Under the Department of Labor's rules, short rest breaks of about 5 to 20 minutes are paid work time. A bona fide meal period is not work time when you are completely relieved of duty, and ordinarily 30 minutes or more is long enough. See the DOL breaks page and 29 CFR 785.19. If you worked through lunch, it was not a meal period for pay purposes, so do not subtract it.
Step 4 of 5: Add up the days
Add the daily totals. Add the hours first, add the minutes, then carry every 60 minutes into one more hour. Here is a sample week:
| Day | Clock in | Clock out | Break | Paid time |
|---|---|---|---|---|
| Monday | 9:00 AM | 5:30 PM | 30 min | 8:00 |
| Tuesday | 8:30 AM | 5:00 PM | 30 min | 8:00 |
| Wednesday | 9:15 AM | 4:45 PM | 30 min | 7:00 |
| Thursday | 7:45 AM | 4:15 PM | 45 min | 7:45 |
| Friday | 10:00 AM | 3:20 PM | none | 5:20 |
| Week | 36:05 |
The hours are 8 + 8 + 7 + 7 + 5 = 35. The minutes are 45 + 20 = 65, which is 1 hour and 5 minutes. So the week is 36 hours 5 minutes, written 36:05. Type the same times into a weekly time card to check it. For a two week pay period, the Biweekly Timesheet Calculator shows a subtotal for each week.
Step 5 of 5: Convert to decimal hours
Payroll systems often want decimal hours. Divide the minutes by 60 and add them to the hours. 5 minutes is 5 / 60 = 0.0833, so 36:05 is 36.08 hours at two decimal places. At $20.00 an hour, that is 36.0833 x $20.00 = $721.67 gross. To skip the division, convert hours and minutes to decimal or look the minutes up on the minutes-to-decimal chart.
Convert the week total once, not each day. Rounding every day to two places and then adding can land a hundredth of an hour away from the exact answer.
Questions people ask
How do you calculate hours worked in a day?
Subtract the clock in time from the clock out time, then subtract any unpaid break. 8:00 AM to 4:30 PM is 8:30, and a 30 minute unpaid lunch leaves 8:00.
How do you calculate hours worked in a week?
Work out each day, then add the days. Add the hours, add the minutes, and carry every 60 minutes into one more hour. A week of five 8:00 days is 40:00.
Do I subtract my lunch break?
Only if it was an unpaid meal period where you were fully relieved of duty. Short rest breaks are paid and stay in your hours. See 29 CFR 785.19 and the DOL breaks page.
How do I calculate hours worked with minutes?
Do the minutes separately from the hours, then combine them. If the minutes pass 60, move 60 of them into an hour. 7 hours 45 minutes plus 5 hours 20 minutes is 12 hours 65 minutes, which is 13 hours 5 minutes.
About this guide
The arithmetic in this guide is the same arithmetic the calculators run, and I checked the sample week above against the Time Card Calculator before publishing: it gives 36:05 and 36.08 hours.
The rules about paid rest breaks and unpaid meal periods come from the Department of Labor's breaks page and 29 CFR 785.19. Everything else here is arithmetic, so there is no outside rule to cite.
I last checked the sources linked on this page on October 8, 2026.
This calculator gives estimates for checking and planning pay. It is not legal, tax or payroll advice. Your employer's pay policy, your contract and the law where you work decide what you are owed.