Guide
How to Calculate Hours Worked
Calculating hours worked is subtraction plus one conversion: the elapsed time between clock-in and clock-out, minus unpaid breaks, converted to decimal hours for payroll. Simple in principle — but overnight shifts, multiple breaks, and the minutes-to-decimal step catch people out. Here is the full method with worked examples.
The four steps
- Put both times in the same format. A 24-hour clock is easiest for arithmetic: 1:30 PM becomes 13:30, 9:00 AM stays 09:00.
- Subtract start from end. 08:00 to 16:30 is 8 hours 30 minutes.
- Subtract unpaid breaks. A 30-minute unpaid lunch leaves 8 hours 0 minutes.
- Convert minutes to a decimal by dividing by 60. 30 ÷ 60 = 0.5, so the day is 8.00 hours.
hours worked = (end − start) − unpaid break, then minutes ÷ 60
Worked example: a single day
You clock in at 7:45 AM, take an unpaid 45-minute lunch, and clock out at 5:15 PM.
- 07:45 to 17:15 is 9 hours 30 minutes.
- Minus 45 minutes unpaid break = 8 hours 45 minutes.
- 45 ÷ 60 = 0.75, so the day is 8.75 hours.
Overnight shifts
When the end time is earlier than the start time, the shift crossed
midnight. Add 24 hours to the end time before subtracting. A shift from
22:00 to 06:00 is (06:00 + 24:00) − 22:00 = 8 hours. If
there was a 30-minute unpaid break, the paid total is 7.5 hours.
For overtime and daily-overtime states, an overnight shift is usually credited to the day it started, but check your employer's workweek definition — see what is a pay period.
Split shifts and multiple breaks
If you leave and come back, treat each segment separately and add them:
| Segment | In | Out | Paid time |
|---|---|---|---|
| Morning | 09:00 | 12:30 | 3h 30m |
| Afternoon | 16:00 | 20:00 | 4h 00m |
| Total | 7h 30m = 7.50 |
The unpaid gap between 12:30 and 16:00 is not worked time. Some states require a "split shift premium" (extra pay for the day), which is separate from hours worked.
Minutes to decimal — the common mistake
7 hours 45 minutes is 7.75, not 7.45. The minutes are a fraction of 60, not of 100.
| Minutes | Decimal | Minutes | Decimal |
|---|---|---|---|
| 5 | 0.08 | 35 | 0.58 |
| 10 | 0.17 | 40 | 0.67 |
| 15 | 0.25 | 45 | 0.75 |
| 20 | 0.33 | 50 | 0.83 |
| 30 | 0.50 | 55 | 0.92 |
The full 1–59 chart and the method for keeping the repeating decimals exact are in how to convert minutes to decimal hours.
Which time counts as "worked"?
Under the FLSA, compensable time is broader than time at your main task:
- Short breaks (roughly 5–20 minutes) are generally paid; bona fide meal breaks of 30 minutes or more, free of duties, are not.
- Work before or after a punch — setup, security checks, required gear — is usually compensable.
- Waiting time is paid if you are "engaged to wait"; unpaid if you are genuinely free and off duty.
- Travel between job sites during the day is paid; a normal home-to-work commute is not.
- On-call time is paid if restrictions mean you cannot use it for your own purposes.
A full week
Add the daily decimal totals. Overtime, where it applies, is calculated on the weekly total (over 40 hours under US federal law, over 44 in Ontario), not on the pay period. See how to calculate overtime pay.
| Day | Worked |
|---|---|
| Mon | 8.00 |
| Tue | 8.75 |
| Wed | 7.50 |
| Thu | 8.25 |
| Fri | 9.00 |
| Total | 41.50 → 40 regular + 1.5 overtime |
Rounding
Many employers round each punch to the nearest quarter or tenth of an hour. In the US, rounding is allowed only if it does not consistently favour the employer over time — the "7-minute rule" and its limits are covered in time clock rounding rules. Record your actual times; round only if your workplace policy requires it.
Frequently asked questions
How do I calculate hours and minutes for payroll?
Work out hours and minutes first, then convert the minutes to a decimal by dividing by 60. Payroll multiplies decimal hours by your rate.
Do I subtract lunch if I worked through it?
No. You are only unpaid for a meal break if you were actually relieved of duty. Working through lunch is paid time; note it on your record.
How are hours worked calculated on a time card?
Per day: clock-out minus clock-in, minus unpaid breaks. Then sum the days for the pay period. See how time cards work.
Let a calculator do it
- Hours Worked Calculator — one shift or a split shift, with a break.
- Time Card Calculator — a full week, with overtime and gross pay.
- Time Clock Calculator — a list of clock-in/out punches for payroll.