Overtime is a multiple, not a separate rate
This is the thing the tool is built around. You enter your basic rate once, and every enhanced band is worked out from it: time and a half is 1.5 times basic, double time is 2 times basic. You never type an overtime rate directly.
That is deliberate, because the common mistake is entering an already-enhanced figure as the base and then applying a multiplier on top of it. Somebody on £15 who is told their overtime rate is £22.50 and then applies time and a half to that ends up at £33.75 an hour, which is double and a quarter. It looks plausible on a payslip and it is wrong.
What the law requires
There is no legal right to be paid extra for overtime in the UK. Time and a half and double time are contractual, not statutory, and what you get depends entirely on your contract, your collective agreement or your employer's custom.
What the law does require is that your average pay across all the hours you work does not fall below the National Minimum or National Living Wage for your age. So overtime cannot be paid at a lower rate that drags the average under the minimum, and unpaid overtime that pushes the average below it is unlawful even where the basic rate is compliant.
Working hours are separately capped at an average of 48 a week over a 17 week reference period unless the worker has signed an individual opt-out. Overtime counts toward that average.
Adding your own rates
Time and a half and double time are there by default, but plenty of agreements use others: a quarter extra for evenings, a third for Saturdays, double and a half for bank holidays, or a flat shift allowance dressed up as a multiplier. Add as many bands as your agreement uses and name them whatever your payslip calls them, so the output matches the document you are checking it against.
Britain is unusual, and it is worth knowing which way round
Most people assume overtime pay is a basic legal right everywhere and that Britain is normal. It is the other way round. In the United States the Fair Labor Standards Act requires at least one and a half times the regular rate for hours worked beyond 40 in a week for non-exempt employees, and that is federal law rather than a matter for the contract. Several states go further: California pays overtime on a daily basis past eight hours as well as a weekly one.
Australia sits in the middle. Overtime is set by the modern award or enterprise agreement covering the job rather than by a single national rule, which is why two people doing similar work on different awards get different penalty rates. Canada is provincial in the same way an employment standard usually is, with the weekly threshold differing between provinces.
So the practical advice inverts depending on where you are standing. In Britain the question is what your contract says, because nothing else will help you. In America the question is whether you are classified as exempt, because if you are not, the entitlement exists whatever the contract says, and misclassification is the fight rather than the rate.
This calculator does the arithmetic either way, since a multiple of a basic rate is a multiple of a basic rate. What it cannot do is tell you which threshold applies to you, so check your own award, contract or state rule for the hours figure before relying on the total.
What this figure is and is not
The total here is gross pay: what you earned before anything comes off. Income tax, National Insurance, pension contributions and any student loan repayment all come out after this, and how much depends on your tax code and your earnings across the whole year rather than on this week alone.
Use this to check that the hours and rates on a payslip have been added up correctly, which is the most common place an error actually appears. For what lands in your account, the take-home pay calculator handles the deductions.
Common questions
Is overtime a separate pay rate or a multiple of my basic rate?
A multiple. You enter your basic rate once, and every enhanced band such as time and a half or double time is worked out from it, at 1.5 or 2 times basic. You never type an overtime rate directly, which avoids the common mistake of taking an already-enhanced figure as the base and multiplying it again.
What happens if I apply time and a half to a rate that is already enhanced?
You end up overpaid or underpaid without realising it. Somebody on £15 an hour told their overtime rate is £22.50, who then applies time and a half to that £22.50, ends up at £33.75, which is double and a quarter rather than time and a half, and it looks plausible on a payslip while being wrong.
Am I legally entitled to be paid extra for working overtime in the UK?
No. Time and a half and double time are contractual, not statutory, so what you actually get depends on your contract, a collective agreement or your employer's custom. What the law does require is that your average pay across all hours worked does not fall below the National Minimum or National Living Wage for your age.
Is there a limit on how many hours of overtime I can work?
Working hours are capped at an average of 48 a week over a 17 week reference period, unless you have signed an individual opt-out, and overtime counts toward that average.
Can I add my own overtime rates beyond time and a half and double time?
Yes. Plenty of agreements use others, such as a quarter extra for evenings, a third for Saturdays, or double and a half for bank holidays. You can add as many bands as your agreement uses and name them whatever your payslip calls them.
Is the total this calculator gives me my take-home pay?
No, it is gross pay, what you earned before anything comes off. Income tax, National Insurance, pension contributions and any student loan repayment are all deducted after this, and how much depends on your tax code and earnings across the whole year.