The Hours Calculator tells you exactly how long you worked between two clock times. Enter a start, an end and any unpaid break, and it returns your total in three formats: HH:MM, total minutes, and decimal hours — the same decimal format used by most timesheet and payroll systems.
How it works
Both clock times are converted to total minutes past midnight. The end is subtracted from the start; if the answer is negative the calculator adds 24 hours to correctly measure overnight shifts. Break minutes are then subtracted, the difference is broken back into hours and minutes, and divided by 60 to give decimal hours.
The formulas
- Start minutes = start_hour × 60 + start_min; same for end.
- Diff = end − start; if Diff < 0 then Diff = Diff + 1,440.
- Worked = Diff − break_minutes.
- Decimal hours = Worked ÷ 60.
Worked examples
Standard day shift
09:00 → 17:30 with a 30-minute break = 8h 00m = 8.00 decimal hours.
Overnight shift
22:00 → 06:30, 45-minute break. Raw = 6:30 − 22:00 = −15:30 → +24h = 8h 30m − 0h 45m = 7h 45m (7.75h).
Split freelance session
14:15 → 18:50, no break = 4h 35m = 4.58 decimal hours.
Who uses this calculator
- Hourly employees checking their weekly hours before signing a timesheet.
- Freelancers and consultants billing clients in decimal hours.
- Managers building schedules and rota rules around overtime thresholds.
- Nurses, drivers and factory workers running overnight and rotating shifts.
Tips and common mistakes
- Enter clock times in 24-hour format (17:30 not 5:30 PM) to avoid AM/PM confusion.
- Unpaid breaks are subtracted; short paid breaks should stay in.
- Round only for payroll — keep the raw minutes for your own record.
- 4h 30m equals 4.50 decimal hours, not 4.30. Multiply the minutes by 1/60.