- Hours = end time − start time − unpaid break.
- End time earlier than start? The shift crossed midnight: add 24 hours.
- Decimal hours = hours + minutes ÷ 60, so 7h 45m = 7.75.
How many hours are between two times?
Subtract the start time from the end time, and if the result is negative add 24 hours, because the shift crossed midnight.
The easy way by hand is to switch to a 24-hour clock first. 5:30 PM becomes 17:30, so 9:00 AM to 5:30 PM is 17:30 − 9:00 = 8 hours 30 minutes. For a night shift, 10:00 PM (22:00) to 6:30 AM (6:30) gives −15:30, plus 24 hours = 8 hours 30 minutes.
How long are common shifts?
Most full shifts land between 7.5 and 12 hours once the unpaid break comes off.
| Shift | Break | Hours | Decimal |
|---|---|---|---|
| 9:00 AM – 5:00 PM | 30 min | 7:30 | 7.50 |
| 9:00 AM – 5:30 PM | 30 min | 8:00 | 8.00 |
| 8:00 AM – 4:30 PM | 30 min | 8:00 | 8.00 |
| 7:00 AM – 7:30 PM | 30 min | 12:00 | 12.00 |
| 10:00 PM – 6:30 AM | 30 min | 8:00 | 8.00 |
| 11:00 AM – 2:00 PM + 5:00 PM – 9:00 PM | none | 7:00 | 7.00 |
Should I subtract my lunch break?
Subtract a break only if it was unpaid; in the US, meal breaks of 30 minutes or more where you are fully off duty are usually unpaid, while short rest breaks are usually paid.
If you ate at the register or kept answering the phone, that time generally counts as work. State rules vary, so check your state labor department if you're not sure.
Is there an app that counts my hours for me?
Yes. Timelog, our iPhone app, records each shift as you clock in and out, deducts breaks and handles overnight shifts, so the total is already done at the end of the week.
It keeps a weekly timesheet with your hours and estimated pay, and stores everything on your phone with no account. It is a personal record, not a payroll system.
Frequently asked questions
How many hours is 9 AM to 5 PM?
9 AM to 5 PM is 8 hours. With a 30 minute unpaid lunch it is 7 hours 30 minutes, or 7.5 hours in decimal.
How do I calculate hours between two times?
Subtract the start time from the end time. If the end time is earlier than the start, the shift crossed midnight, so add 24 hours first. Then subtract any unpaid break. 10:00 PM to 6:30 AM is 8 hours 30 minutes; minus a 30 minute break is 8 hours.
Does the work hours calculator handle split shifts?
Yes. Add one row per stretch of work, for example 11 AM to 2 PM and 5 PM to 9 PM, and the calculator adds them up: 3 + 4 = 7 hours.
Why are the times in 15-minute steps?
Dropdowns are faster than typing on a phone, and most schedules and time clocks work in quarter hours. For exact minutes from a punch clock, use the time card calculator or log shifts in an app as you work.
Is this work hours calculator free?
Yes. It is free, needs no sign-up, and runs in your browser. Your entries are only remembered on this device.