Hours Calculator
Work out the hours between a start and end time, subtract your break, and optionally see the pay — with decimal hours for payroll.
How hours are calculated
Decimal hours = hours + minutes ÷ 60
9:00 AM to 5:30 PM is 8.5 hours; minus a 30-minute lunch = 8.0 hours (8:00 in h:mm, 8.00 decimal). At $20/hr that's $160.
10:00 PM to 6:00 AM (crosses midnight) minus a 20-minute break: 480 minutes worked − 20 = 460 minutes = 7h 40m (7.67 decimal hours). At $18/hour that's 7.6667 × $18 ≈ $138.00.
Timesheets, overnight shifts, and decimal hours
Payroll systems use decimal hours (8.25, not 8:15), which is why this tool shows both. If the end time is before the start time, the calculator assumes an overnight shift and adds 24 hours, so a 10 PM–6 AM shift correctly reads 8 hours. Add your rate to see gross pay for the shift; for overtime beyond 40 hours a week, use the overtime calculator, and to convert an hourly wage to an annual salary, the salary calculator.
Minutes to decimal hours, at a glance
| Minutes | Decimal hours |
|---|---|
| 15 | 0.25 |
| 20 | 0.33 |
| 30 | 0.50 |
| 40 | 0.67 |
| 45 | 0.75 |
Common timesheet mistakes
- Rounding decimal hours each day instead of only at the pay-period total. Rounding 7.67 down to 7.5 daily compounds error over a two-week period; most payroll systems round only the final total.
- Deducting a break that's legally paid. A short paid break (often under 20 minutes, depending on state law) should not be subtracted, while an unpaid 30-minute lunch should be.
- Entering an end time earlier than the start time by mistake. The calculator assumes any such entry is an overnight shift and silently adds 24 hours — a genuine typo can produce a plausible-looking but wrong result.
Frequently asked questions
How do I calculate hours worked?
End − start − unpaid break. 9:00–5:30 with a 30-min lunch = 8.0 hours.
How do I convert to decimal hours?
Minutes ÷ 60 added to hours. 8h 15m = 8.25.
How does an overnight shift work?
If end is before start, 24 hours is added. 10 PM–6 AM = 8 hours.
Are unpaid breaks legally required to be deducted?
Under U.S. federal law, unpaid meal breaks of 30+ minutes can be excluded; short breaks under ~20 minutes are usually paid time. Rules vary by state.
How do I calculate hours for a split shift?
Run the calculator once per continuous block and add the decimal-hour results — 9-1 plus 4-8 is two 4-hour calculations totaling 8 hours.
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Last reviewed: September 2026.