Hours Calculator
Count the hours and minutes between a start and end time — with an unpaid break subtracted and overnight shifts handled automatically. Switch modes to count hours between two different dates, and get the decimal hours payroll systems expect.
If the end time is earlier than the start time, the shift is assumed to run overnight into the next day.
How the hours between two times are counted
The calculator converts both clock times to minutes since midnight and subtracts. If the end time is at or before the start time, it assumes you worked past midnight and adds 24 hours — so 10:00 PM to 6:00 AM correctly returns 8 hours. Your unpaid break is then removed. Payroll software usually wants decimal hours (8h 30m = 8.50), so both formats are shown; the date mode does the same math across calendar days for multi-day spans.
How it’s calculated
Minutes = end − start (+ 1,440 if the shift crosses midnight) − break minutes. Decimal hours = minutes ÷ 60. Date mode counts real calendar time using UTC day math, so results are exact across month ends and leap days and are never distorted by daylight-saving clock changes.
Results update as you type. Break rules vary by employer and state — check what counts as paid time before invoicing or running payroll.
Hours in common time periods
| Period | Hours |
|---|---|
| Day | 24 |
| Week | 168 |
| Month | 672–744 (730.5 on average) |
| Year | 8,760 (8,784 in a leap year; 8,766 average) |
| Standard U.S. work year | 2,080 (40 h × 52 weeks) |
Worked example
A shift from 8:30 AM to 5:15 PM is 8 h 45 m on the clock. Subtract a 45-minute unpaid lunch and you get 8h 0m — exactly 8.00 decimal hours (480 minutes). In date mode, July 1, 2026 9:00 AM to July 3, 2026 5:30 PM spans 2 days 8h 30m: 56 hours 30 minutes, or 56.50 decimal hours before any break.
Common mistakes
- Typing 7:30 into payroll as 7.3 hours — 7 h 30 m is 7.50 decimal hours.
- Forgetting the shift crossed midnight and reporting a negative or 16-hour day.
- Subtracting paid rest breaks — only unpaid time (usually meal periods) should come off.
- Mixing up AM and PM — the pickers here use your device’s clock format, so double-check 12:00 entries.
Where it is used
- Filling in timesheets and calculating billable hours for invoices.
- Checking a paycheck against the hours you actually worked.
- Planning shift lengths, on-call windows, or study blocks.
- Measuring how long a job, render, or process ran across several days.
Frequently asked questions
How do decimal hours work?
Divide the minutes by 60: 8 h 30 m is 8.50 hours, 7 h 45 m is 7.75 hours. Payroll systems multiply decimal hours by the hourly rate, which is why 8h 20m shows as 8.33 rather than 8.2.
What happens if my shift crosses midnight?
When the end time is at or before the start time, the calculator adds 24 hours automatically. A 10:00 PM to 6:00 AM shift returns 8 h 0 m and the span line flags it as overnight.
Can I count hours between two different days?
Yes — switch the mode to “Between two dates & times.” July 1 at 9:00 AM to July 3 at 5:30 PM works out to 56 hours 30 minutes (2 days 8.5 hours).
Should breaks be subtracted?
Only unpaid ones. Under U.S. Department of Labor guidance, short rest breaks of roughly 5–20 minutes generally count as paid work time, while bona fide meal periods of 30 minutes or more can be unpaid. Enter just the unpaid portion.
How many working hours are in a year?
A standard 40-hour week over 52 weeks is 2,080 hours. Subtract your holidays and PTO for realistic capacity — 15 days off leaves about 1,960 working hours.