Weekly hours decide overtime, benefits eligibility and your effective hourly rate. The tricky part is not the addition. It is knowing which seven days make up your week.
Step 1: find your workweek
Under federal law a workweek is a fixed, repeating period of 168 hours, which is seven consecutive 24-hour days. It can start on any day and any time, but your employer must apply it consistently. Pay stubs and handbooks usually say, for example, "workweek runs Sunday 12:00 AM to Saturday 11:59 PM."
Step 2: total each day, then each week
Weekly hours = sum of daily hours inside one workweek
Use the hours calculator for each day or the timesheet calculator to do the whole period. Add minutes before converting to decimals to avoid drift.
Common schedules and what they add up to
| Schedule | Calculation | Weekly hours |
|---|---|---|
| 5 days of 8 hours | 5 x 8 | 40 |
| 4 days of 10 hours | 4 x 10 | 40 |
| 3 days of 12 hours | 3 x 12 | 36 |
| 5 days of 7.5 hours | 5 x 7.5 | 37.5 |
| 6 days of 8.5 hours | 6 x 8.5 | 51 (11 overtime hours) |
Averaging hours over several weeks
For planning, an average helps. Divide the total hours by the number of weeks. 168 hours over 4 weeks is 42 hours a week. But for overtime, averages do not apply. Each week stands alone.
Example: week 1 is 50 hours and week 2 is 30 hours. The two-week average is 40, yet week 1 includes 10 overtime hours. At $10 an hour that is $850, not $800.
Where overtime begins
The federal overtime line is more than 40 hours in a workweek. Time over 40 is paid at 1.5 times the regular rate for employees who are not exempt. Daily totals do not matter under the federal rule, so a 12-hour day in a 36-hour week is not federal overtime. Some states set daily limits, so check your state labor department.
Converting between weekly, monthly and yearly hours
- Weekly to yearly: multiply by 52. 40 hours is 2,080 hours a year.
- Yearly to monthly: divide by 12. 2,080 hours is about 173.33 hours a month.
- Monthly to weekly: multiply by 12 and divide by 52. 160 hours a month is about 36.92 hours a week.