Hours Calculator

What happens to the two times

Each time is converted to minutes since midnight: 09:00 becomes 540 and 17:30 becomes 1,050. The start is subtracted from the end, 1,440 minutes are added if the result is zero or negative (the overnight case, and the same-time case), and the break is subtracted last. The default inputs give 1,050 − 540 − 30 = 480 minutes, displayed as 8h 0m, 8 hours and 480 minutes.

An overnight example: 22:00 to 06:00 with a 45-minute break. 360 − 1,320 is negative, so 1,440 is added to give 480, and the break brings it to 435 minutes, shown as 7h 15m or 7.25 hours.

Minutes to decimal hours for timesheets

The decimal figure is the minutes divided by 60 and rounded to two decimal places. Most minute values do not divide evenly, which is why 4 hours 5 minutes is shown as 4.08 rather than 4.0833. The exact minute count sits next to it for anyone who needs the unrounded value.

Boundaries of what it can measure

• It handles one shift at a time. For a weekly total, note the minutes from each day and add them up; there is no multi-row mode.
• Entering the same start and end time is read as a full 24-hour shift, so 1,440 minutes is the longest span it can represent; 08:00 to 08:00 with a 60-minute break shows 23h 0m.
• The break is a single whole number of minutes: a decimal such as 7.5 is rounded to the nearest minute (8) before it is subtracted, and two breaks of 15 and 30 minutes should be entered as 45.
• A break longer than the shift, or a negative break, replaces the result with a prompt to check the inputs rather than showing a negative time.
• Seconds are not supported; the time pickers work in whole minutes.

Rounding rules your employer may apply

The tool reports exact minutes, but payroll departments often round clock times to the nearest quarter hour before paying. In the United States the Fair Labor Standards Act permits this as long as the rounding does not consistently favour the employer, which is where the 7-minute rule comes from: 8:07 rounds down to 8:00 and 8:08 rounds up to 8:15. If your pay slip differs from the figure here by a few minutes a day, rounding is the usual explanation.

Overtime thresholds are another source of difference. A 10-hour shift shows as 10 hours here; whether the last two are paid at a higher rate depends on your contract and local law, not on the arithmetic.

Jobs the calculator is good for

• Filling in a timesheet that wants decimal hours when your clock-in records show times.
• Checking an hourly invoice: multiply the decimal hours by your rate.
• Working out a babysitter's or contractor's time from arrival and departure, minus an unpaid lunch.
• Measuring any interval inside a day, such as parking duration or how long a batch job ran, by treating the break as 0.