About this calculator
Last updated: 16 October 2026. Tax year used: 2026/27, with rates taken from GOV.UK, gov.scot and HMRC guidance and checked in October 2026.
What makes it different
Most rate calculators apply one flat tax percentage. This one works out income tax and Class 4 National Insurance from the real bands, so the tax share rises as your target rises. It has separate Scottish bands, and optional inputs for other income, pension contributions and student loans. The what-if tables show how holidays and billable time change your rate.
What it covers
Income tax for England, Wales, Northern Ireland and Scotland, the personal allowance and its reduction above £100,000, Class 4 National Insurance, personal pension contributions, and student loan repayments (Plans 1, 2, 4, 5 and postgraduate).
What it leaves out
Dividends, savings and property income, voluntary Class 2 National Insurance, the marriage allowance, Gift Aid, business losses, payments on account, the High Income Child Benefit Charge, VAT, limited companies and IR35. Pension tax relief is simplified, and Scottish pension relief can differ slightly. Your own situation may differ.
How the numbers were checked
The tax calculations were compared with published 2026/27 worked examples for self-employed profits of £30,000, £40,000, £50,000 and £60,000, and the Scottish bands were checked by hand against the Scottish Government's published rates. It has not been reviewed by an accountant.
Not tax advice
This is a free, independent tool and is not connected to HMRC or any accountancy firm. It gives estimates only and is not tax, legal or financial advice. Check your own figures with an accountant or HMRC before making decisions.
Privacy
The numbers you enter stay in your browser. This page does not send them anywhere, store them, or use cookies, analytics or advertising.