Why 7 hours 38 minutes is 7.63 and not 7.38
An hour has sixty minutes, not a hundred. So when a payroll system asks for hours as a decimal, it wants the minutes expressed as a fraction of sixty rather than written after a dot.
Thirty eight minutes is 38 divided by 60, which is 0.633. So seven hours and thirty eight minutes is 7.63 hours. Typing 7.38 instead hands back about fifteen minutes. Do that every day and it is over an hour a week, which is roughly a week and a half of unpaid work a year.
It runs the other way too. If a timesheet app tells you somebody worked 7.75 hours and you read that as seven hours seventy five minutes, you will overpay. It is seven hours and forty five minutes.
The values worth memorising
Four of them cover most of what comes up: fifteen minutes is 0.25, thirty is 0.5, forty five is 0.75, and any whole hour is itself. Everything else is on the chart above, which is there to be printed and stuck inside a cupboard door in the site office.
The awkward ones are the values people guess at. Ten minutes is 0.17, not 0.10. Twenty is 0.33. Forty is 0.67. Fifty is 0.83. Those four are where most of the drift comes from, because they look like they should be round numbers and are not.
Rounding, and who decides it
This tool rounds to two decimal places and no further. It deliberately does not round to the nearest quarter hour, even though plenty of employers do, because that is a decision about somebody's pay and it should be made by the person doing the payroll rather than assumed by a website.
If your workplace does round to the nearest quarter or the nearest six minutes, do it after this rather than instead of it, so you can see what the actual figure was before it moved.
Payroll rounds, and it is allowed to
Almost no payroll system pays to the exact minute. The common increments are the nearest minute, the nearest tenth of an hour, which is six minutes, and the nearest quarter of an hour. A tenth is the one most timesheet software uses, which is why so many exported hours land on figures like 7.6 and 7.7 and never on 7.63.
In the United States rounding to the quarter hour is expressly permitted under the Fair Labor Standards Act, on the condition that it is neutral over time rather than always in the employer's favour. That is the well known seven minute rule: up to seven minutes rounds down and eight minutes or more rounds up. Rounding that only ever goes one way is the thing that gets challenged, not the rounding itself.
Britain, Australia and Canada have no equivalent statutory rounding rule, so it is a matter for the contract and for whether the result still clears the minimum wage once averaged. The practical consequence is the same in all four: check which increment your employer uses before arguing about a figure, because a difference of two minutes a day is roughly a full shift a year.
Where this fits
If you are working out a single shift including one that runs past midnight, the hours between two times tool handles the arithmetic and gives you the decimal at the same time. If you are doing a whole week, the timesheet does all seven days and totals them. This one exists for the moment you have a figure in front of you and just need it in the other form.
Common questions
Why is 7 hours 38 minutes written as 7.63 rather than 7.38 in decimal?
Because an hour has sixty minutes, not a hundred, so the minutes have to be expressed as a fraction of sixty. Thirty eight divided by sixty is 0.633, so seven hours thirty eight minutes is 7.63 hours. Typing 7.38 instead hands back about fifteen minutes less than was actually worked.
If a timesheet shows 7.75 hours, how many minutes is that?
Forty five minutes, not seventy five. Reading 7.75 as seven hours and seventy five minutes overpays the person, because 0.75 of an hour is forty five minutes, three quarters of sixty rather than a number out of a hundred.
Which minute-to-decimal conversions are worth memorising?
Four cover most cases: fifteen minutes is 0.25, thirty is 0.5, forty five is 0.75, and any whole hour is itself. The ones people usually guess wrong are ten minutes, which is 0.17 rather than 0.10, twenty at 0.33, forty at 0.67, and fifty at 0.83.
Does this tool round to the nearest quarter hour?
No, and that is deliberate. It rounds to two decimal places only, because rounding to the nearest quarter or six minutes is a decision about somebody's pay that should be made by whoever runs the payroll, not assumed by a website. If your workplace does round, do it after using this figure rather than instead of it.
What is the difference between this tool and the hours between two times calculator?
This tool converts a figure you already have, such as a single shift length, between hours-and-minutes and decimal form. The hours between two times tool works out that figure in the first place from a start and finish time, including shifts that run past midnight, and the timesheet totals a whole week at once.