How to Calculate Hours Worked
A simple method you can do by hand or check with a calculator: subtract, take away breaks, add up the days, and convert to decimal for payroll.
The 4 steps
- Find the time between clock-in and clock-out. 8:30 AM to 5:00 PM is 8 hours 30 minutes.
- Subtract unpaid breaks. Take off a 30-minute lunch to get 8 hours.
- Add the days together. Add hours to hours and minutes to minutes. Every 60 minutes becomes 1 hour.
- Convert to decimal if payroll needs it. Divide the minutes by 60: 25 minutes is 0.42 of an hour, so 39 hours 25 minutes is 39.42 hours.
A full week, worked out
| Day | In | Out | Unpaid break | Hours worked |
|---|---|---|---|---|
| Mon | 8:00 AM | 4:30 PM | 30 min | 8:00 |
| Tue | 9:15 AM | 5:45 PM | 30 min | 8:00 |
| Wed | 8:10 AM | 5:00 PM | 45 min | 8:05 |
| Thu | 8:30 AM | 4:00 PM | 30 min | 7:00 |
| Fri | 10:00 AM | 7:20 PM | 60 min | 8:20 |
| Week total | 39:25 (39.42 hours) | |||
Check Wednesday: 8:10 AM to 5:00 PM is 8 hours 50 minutes. Take off 45 minutes and you have 8 hours 5 minutes. Add the week: 480 + 480 + 485 + 420 + 500 = 2,365 minutes, which is 39 hours 25 minutes.
Overnight shifts
If the clock-out time is earlier than the clock-in time, the shift crossed midnight. Add 24 hours to the out time before you subtract. 10:00 PM to 6:00 AM is 8 hours, because 6:00 AM the next day is 30:00 on a 24-hour clock and 30:00 minus 22:00 is 8 hours.
Which breaks do you take off?
Under US federal rules, short rest breaks of about 5 to 20 minutes count as paid work time, so you do not subtract them. A real meal period, usually 30 minutes or more when the worker is fully relieved from duty, does not have to be paid, so it can be subtracted. Some states have their own meal and rest rules, so check your state labor department. If your employer pays for lunch, do not subtract it.
Common mistakes
- Writing 8:15 as 8.15. An hour has 60 minutes, so 8 hours 15 minutes is 8.25 hours. See the hours to decimal calculator.
- Rounding each day instead of the total. Add the exact minutes first, then convert once.
- Forgetting AM and PM. 8:00 to 5:00 is only valid if you know which is which.
- Counting overtime across two weeks. Overtime is worked out one workweek at a time.
To skip the arithmetic, enter your times in the time card calculator. It shows h:mm and decimal totals, subtracts breaks, handles overnight shifts and works out overtime and pay. For minutes only, use the minutes to hours calculator.
TimeCardPal gives estimates for planning and checking pay. It is not legal, tax or payroll advice. Overtime rules vary by state and job type; check with your state labor department or a payroll professional for your situation.
Frequently asked questions
How do I calculate hours worked from clock-in and clock-out times?
Subtract the in time from the out time, take away any unpaid break, then add up the days. For example, 8:30 AM to 5:00 PM with a 30-minute lunch is 8 hours.
How do I calculate hours worked with minutes?
Work in minutes if it is easier. Convert each day to minutes, add them, then divide by 60. 2,365 minutes is 39 hours 25 minutes (39.42 decimal hours).
How do I calculate hours worked overnight?
If the out time is earlier than the in time, add 24 hours to the out time before subtracting. 10:00 PM to 6:00 AM is 8 hours.
How do I convert hours and minutes to decimal?
Divide the minutes by 60 and add them to the hours. 7 hours 45 minutes is 7 + 0.75 = 7.75 hours.
Do I subtract lunch when calculating hours worked?
Subtract it only if it is unpaid. Under federal rules a meal period of 30 minutes or more when you are fully relieved of duty is usually unpaid, while short rest breaks are paid.
How many hours is a full-time week?
Many employers treat 40 hours a week as full time, but the legal definition varies by employer, state and purpose.