Estimates only
Every figure produced by the calculators on this site is an estimate. The calculators use the standard UK pro rata method — the full-time figure multiplied by your share of the full-time week — and published tax and National Insurance rates. Real payroll has more moving parts: your contract's definition of the full-time week, enhanced holiday schemes, unpaid leave, overtime, and changes to your hours part-way through a year can all move the final number.
Treat our results as a careful estimate to check against, not as the figure itself. If your payslip matches, that is reassuring; if not, the difference deserves a question — and may be entirely innocent.
Tax and take-home estimates
Take-home figures use income tax and National Insurance rates for the 2026/27 tax year, including the Scottish income tax bands when you select Scotland. They assume the standard personal allowance and tax code. Student loan repayments are not included. If your tax code is not the standard one, if you earn over £100,000 (where the personal allowance reduces), or if you have other income, your actual take-home pay will differ from the estimate.
Where a pension percentage is entered, the calculators treat the contribution as salary sacrifice. Not all schemes work that way: members of the Teachers' Pension Scheme, for instance, pay contributions under that scheme's own rules, so a teacher's payslip will not match a salary-sacrifice estimate exactly. The pension figure here is a guide to the size of the deduction, not what your scheme will take.
Check your contract and payslip
Your employment contract and your payslip are the documents that decide your pay and holiday. Use our results as a checking tool: if your figure and ours differ, the difference is a prompt to ask your employer to show their working, not proof either figure is wrong. Most differences have a plain explanation: a different full-time week in the contract, a holiday scheme more generous than the statutory minimum, or a rounding convention in the payroll system.
Not financial or legal advice
This site provides general information about how pro rata calculations work. It does not provide financial advice, tax advice, legal advice or employment advice. The rules described here reflect UK practice as at October 2026, including the irregular-hours holiday accrual rules in force for leave years beginning on or after 1 April 2024. Tax thresholds, statutory rates and holiday law change over time.
Official guidance
For official guidance, see GOV.UK — holiday entitlement rights and ACAS — part-time workers, or contact ACAS for free advice about workplace rights.