Overtime pay calculator
Work out a week's pay with overtime and weekend hours. Enter your rate and multipliers once, then your hours. You'll get each line and the total, rounded to the penny, ready to copy onto an invoice.
The method
- Work out the hourly rate. If you're on a day rate, that's the day rate ÷ standard hours, kept at full precision.
- Multiply the rate by the multiplier for each type of hour.
- Multiply by the hours, then round that line to the nearest penny.
- Add up the rounded lines.
With the default figures (£165 day, 8 hours, 40 weekday hours, 5 overtime hours at ×1.25, 4 Saturday hours at ×1.25), the result is £825.00 + £128.91 + £103.13 = £1,057.04.
Common multipliers
| Name | Multiplier | On £20/h |
|---|---|---|
| Time and a quarter | ×1.25 | £25.00 |
| Time and a third | ×1.333… | £26.67 |
| Time and a half | ×1.5 | £30.00 |
| Double time | ×2 | £40.00 |
Is overtime pay a legal right?
GOV.UK explains that employers don't have to pay workers for overtime, although average pay over the hours worked mustn't fall below the National Minimum Wage. Any enhanced rate depends on your contract. For self-employed contractors, overtime and weekend rates are whatever you agree with your client, so put them in writing before the work starts.
Putting it on an invoice
Show the hours and rate on each line so the client can check it. "Overtime – 5h @ £25.78 = £128.91" is clear. See our overtime on invoices guide for layouts, and our weekly template for a day-by-day version.
Frequently asked questions
How do I calculate time and a half?
Multiply your hourly rate by 1.5, then by the overtime hours. For example, £20 × 1.5 × 4 hours = £120.
Does my employer have to pay overtime?
Not necessarily. It depends on your contract, although average pay must not fall below the minimum wage.
Why round each line instead of the rate?
Rounding the rate first creates small errors that add up over many hours. Rounding each line keeps the total accurate to the penny.
Sources
This guide is general information, not legal, tax or financial advice. Rules and rates change, so check the linked GOV.UK pages for the current position.