9 am to 5 pm is 8 hours. With an unpaid 30-minute lunch it's 7.5 hours of work, and with a 1-hour lunch it's 7 hours. Over a five-day week that's 40, 37.5 or 35 hours.
Below is a chart of the shifts people ask about most, from 7 to 3 and 8 to 5 to 12-hour and overnight shifts. For any other start and end time, the Time Duration Calculator gives the exact hours and minutes.
Shift hours chart
| Shift | Total hours | With 30-min break | With 1-hour break |
| 6 am – 2 pm | 8 | 7.5 | 7 |
| 7 am – 3 pm | 8 | 7.5 | 7 |
| 7 am – 3:30 pm | 8.5 | 8 | 7.5 |
| 8 am – 4 pm | 8 | 7.5 | 7 |
| 8 am – 4:30 pm | 8.5 | 8 | 7.5 |
| 8 am – 5 pm | 9 | 8.5 | 8 |
| 8:30 am – 5 pm | 8.5 | 8 | 7.5 |
| 9 am – 5 pm | 8 | 7.5 | 7 |
| 9 am – 5:30 pm | 8.5 | 8 | 7.5 |
| 9 am – 6 pm | 9 | 8.5 | 8 |
| 10 am – 6 pm | 8 | 7.5 | 7 |
| 10 am – 7 pm | 9 | 8.5 | 8 |
| 3 pm – 11 pm | 8 | 7.5 | 7 |
A pattern worth noticing: the very common 8 to 5 and 9 to 6 shifts are 9 hours long, which is why they usually come with a 1-hour lunch. After the break you're back to an 8-hour working day.
12-hour shifts
| Shift | Total hours | With 30-min break | With 1-hour break |
| 6 am – 6 pm | 12 | 11.5 | 11 |
| 7 am – 7 pm | 12 | 11.5 | 11 |
| 8 am – 8 pm | 12 | 11.5 | 11 |
| 7 pm – 7 am (night) | 12 | 11.5 | 11 |
Three 12-hour shifts a week is 36 hours, which is common in nursing and other healthcare jobs. Four 12-hour shifts is 48 hours, so in the US the hours over 40 that week are usually overtime.
Overnight shifts
Night shifts look confusing because the end time is "smaller" than the start time. The easy way is to split the shift at midnight:
• 11 pm to 7 am: 1 hour before midnight + 7 hours after = 8 hours.
• 10 pm to 6 am: 2 hours + 6 hours = 8 hours.
• 7 pm to 7 am: 5 hours + 7 hours = 12 hours.
Another way is 24-hour time: 11 pm is 23:00 and 7 am is 07:00, so add 24 to the end time (31:00) and subtract (31 − 23 = 8). If AM and PM around midnight trip you up, see Is 12 AM Midnight or Noon? or convert with the Military Time Converter.
Hours per week for common schedules
| Schedule | Hours per week |
| 5 × 8-hour days (paid lunch) | 40 |
| 5 × 9 to 5 with a 30-min unpaid lunch | 37.5 |
| 5 × 8 to 5 with a 1-hour unpaid lunch | 40 |
| 4 × 10-hour days ("4/10") | 40 |
| 3 × 12-hour shifts | 36 |
| 4 × 12-hour shifts | 48 |
Want to see what those hours mean for pay? $20 an Hour Is How Much? shows weekly, biweekly and yearly pay for 40 and 37.5-hour weeks.
Are breaks counted as work hours?
In the US, the Department of Labor's rules under federal law are:
• Short breaks (usually 5 to 20 minutes) are counted as work time and must be paid.
• Meal periods (typically 30 minutes or more) are not work time, as long as you're fully relieved of duties during them.
• Federal law doesn't require employers to give lunch or coffee breaks at all, though some states do.
So a 9-to-5 job with a 30-minute unpaid lunch is 7.5 paid hours, but two 15-minute coffee breaks in the same day don't reduce your hours. For converting times like 7 hours 40 minutes into decimal hours for a timesheet, see How to Calculate Hours Worked for Payroll.
Break rules above are US federal rules. State laws and your employment contract can add requirements.
Working an unusual shift? Enter your exact start and end times in the Time Duration Calculator. It handles minutes, seconds and shifts that cross midnight.
