Hours Worked Calculator

What is an hours worked calculator

An hours calculator takes the two times at the ends of a shift, subtracts any break that is not paid, and tells you how long you actually worked. That sounds like something you could do in your head, and for 09:00 to 17:00 you can. The reason a tool exists is everything that is not that: a shift that crosses midnight, a half-hour break on a nine-and-a-quarter-hour day, and the fact that the answer has to come out in two different number systems depending on who is asking for it.

This one takes a start, an end and an unpaid break, and gives you the result in hours and minutes for the person reading it and in decimal for the payroll system that will multiply it by a rate. Both are below, together, because transcribing one into the other by hand is where the errors come from.

How to calculate hours worked

Subtract the start time from the end time, then subtract any unpaid break. 08:30 to 17:15 is 8 hours 45 minutes; take off a 30 minute lunch and the shift is 8 hours 15 minutes worked. Doing it in minutes rather than in hours and minutes is what keeps it straight: 08:30 is 510 minutes past midnight, 17:15 is 1,035, the difference is 525, less 30 is 495, and 495 minutes is 8 hours 15.

If the end time is earlier than the start time the shift crossed midnight, so add 24 hours to the end before subtracting. 22:00 to 06:00 is not minus 16 hours, it is 8. Then divide the minutes by 60 for the decimal form payroll wants: 495 ÷ 60 is 8.25, not 8.15.

• Work in minutes convert both times to minutes past midnight, subtract, then convert back once at the end. Carrying hours and minutes through every step is where the borrowing goes wrong.
• Take the unpaid break off the total not off the end time. The two give the same answer here and stop doing so the moment there is more than one break.
• Add 24 hours for an overnight before subtracting, never after.
• Convert to decimal last minutes ÷ 60, once, from the final minute count. Rounding each step separately is how a week drifts by a few minutes.

Clock time against decimal hours: the difference

This is the mistake that costs people money, and it comes from the clock being base 60 while the calculator is base 10. A shift from 09:15 to 17:45 is eight hours and thirty minutes. Written as 8.30 and multiplied by an hourly rate, it underpays by eighteen minutes an occurrence, because 30 minutes is 0.5 of an hour, not 0.30.

The conversion is minutes ÷ 60. Fifteen minutes is 0.25, twenty is 0.33, forty-five is 0.75. Payroll systems want the decimal form; a timesheet a person checks wants hours and minutes. Giving both, from the same minute count, is the only way the two cannot drift apart.

Which breaks come off the hours worked

• An unpaid break comes off the lunch you clock out for is not time worked, so it is subtracted. This is the field to fill.
• A paid rest break does not it is already inside the shift, so subtracting it would be counting it twice.
• A break longer than the shift is rejected rather than producing a negative total. It is almost always minutes entered as hours: 60 meaning an hour rather than sixty minutes.
• Two breaks add up enter the total unpaid minutes. The calculator does not care how many separate breaks they were.

How to calculate hours for a night shift

A shift that starts at 22:00 and ends at 06:00 has an end time numerically smaller than its start, and a naive subtraction gives minus sixteen hours. Reading it as running into the next day gives eight, which is what was worked. That rule is what makes this usable in hospitality, healthcare, logistics and security, where the overnight shift is the normal case rather than the exception.

The one thing a start-and-end calculator cannot see is a daylight-saving change. On the night the clocks go forward, a 22:00–06:00 shift is seven hours on the wall clock and the worker was there for seven; on the night they go back it is nine. If your shift crossed that night, add or subtract the hour yourself, and check your contract, because whether it is paid differs by employer.

What an hours worked calculator does not do

This does one shift. For a whole week of them, with a weekly total and overtime flagged, use the time card calculator: it takes the same fields seven times over and can fill them from a CSV export of your punch clock. For the gap between two times with no break and no work in it, the time duration calculator is simpler. For the money, the overtime calculator splits regular from premium hours.

And none of them is an employment-law tool. This counts the hours you were there. Whether they attract a premium, breach a daily rest rule or count toward an overtime threshold depends on your country, sector and contract, which differ too much for a calculator to guess at honestly.