Quick answer: Hours worked = end time − start time − unpaid breaks. Example: 8:30 AM to 5:15 PM with a 45-minute lunch is 8 hours 0 minutes, or 8.00 hours. Add up each day for a weekly total, or use our free Working Hours Calculator.
Whether you are filling in a timesheet, checking a payslip or billing a client, adding up hours by hand is easy to get wrong, especially across lunch breaks and midnight shifts. Here is the simple method, with examples and a table for converting minutes.
The formula
Hours worked = finish time − start time − unpaid break time. Use 24-hour time to avoid AM/PM mistakes: 5:15 PM becomes 17:15. If a shift passes midnight, add 24 hours to the finish time before subtracting.
Worked example
- Start 08:30, finish 17:15: 17:15 − 08:30 = 8 hours 45 minutes.
- Subtract a 45-minute unpaid lunch: 8 h 45 m − 45 m = 8 hours 0 minutes.
- Night shift 22:00 to 06:30 with a 30-minute break: (06:30 + 24:00) − 22:00 = 8 h 30 m, minus 30 m = 8 hours.
Convert minutes to decimal hours
Payroll and invoices usually need decimal hours. Divide the minutes by 60: 45 minutes = 45 ÷ 60 = 0.75, so 7 h 45 m = 7.75 hours.
| Minutes | Decimal hours |
|---|---|
| 5 | 0.08 |
| 10 | 0.17 |
| 15 | 0.25 |
| 20 | 0.33 |
| 30 | 0.50 |
| 40 | 0.67 |
| 45 | 0.75 |
| 50 | 0.83 |
Weekly total and overtime
Add each day’s hours for the week. In the United States, federal law (the Fair Labor Standards Act) requires most hourly, non-exempt employees to be paid at least 1.5 times their regular rate for hours over 40 in a workweek, and some states, such as California, also count daily overtime. Rules differ in other countries, including Pakistan and India, so check your local labour law or employment contract.
Work out your pay
Multiply regular hours by your hourly rate and overtime hours by the overtime rate. Example: 45 hours at $20 an hour with overtime after 40 hours = 40 × $20 + 5 × $30 = $950. The Working Hours Calculator does this automatically and can export your timesheet as a CSV.
Frequently asked questions
Are lunch breaks counted as hours worked?
Unpaid meal breaks are subtracted. Short paid rest breaks are usually counted as work time; check your employer’s policy and local law.
How do I calculate hours from 9 to 5?
9:00 to 17:00 is 8 hours. With a 1-hour unpaid lunch it is 7 hours.
How many work hours are in a year?
A full-time 40-hour week for 52 weeks is 2,080 hours before holidays and leave.