Guide
How to Calculate Hours Worked
Calculating hours worked is subtraction plus one conversion: elapsed time between clock-in and clock-out, minus unpaid breaks, converted to decimal hours for payroll. Here is the method, with the parts that trip people up.
The four steps
- Write both times in the same format. Convert to a 24-hour clock if that is easier: 1:30 PM becomes 13:30.
- Subtract the start time from the end time. 8:00 to 16:30 is 8 hours 30 minutes.
- Subtract unpaid breaks. A 30-minute unpaid lunch leaves 8 hours 0 minutes.
- Convert the 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
Overnight shifts
When the end time is earlier than the start time, the shift crossed midnight. Add 24 hours before subtracting. A shift from 22:00 to 06:00 is (06:00 + 24:00) − 22:00 = 8 hours.
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 |
|---|---|
| 15 | 0.25 |
| 20 | 0.33 |
| 30 | 0.50 |
| 45 | 0.75 |
| 50 | 0.83 |
The Decimal Hours Calculator has the full 0–59 chart and a bulk converter.
Rounding
Many employers round each punch to the nearest quarter hour or tenth of an hour. In the US, rounding is allowed under the Fair Labor Standards Act only if it does not consistently favour the employer over time. The well-known "7-minute rule" rounds 1–7 minutes down and 8–14 minutes up to the nearest quarter hour. Record your actual times; round only if your workplace policy says to.
A full week
Add the daily decimal totals. Overtime, where it applies, is usually calculated on the weekly total (over 40 hours under US federal law, over 44 in Ontario). See how to calculate overtime pay.
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.