Fullworkings UK tax and finance calculators
All tools4 tools

Calculators that show their working.

Every rate on this site is read from a dated file rather than written into a page. Each one records the gov.uk page it came from, the dates it applies between, and when a person last checked it. The calculators say which figures they used and where those figures came from.

Pay and employment

Take-home payWhat is left of a salary after tax, National Insurance, pension and student loan. 2026-27
Student loan repaymentsWhat you repay each month, and what every plan would cost on the same salary. 2026-27

Family

Child benefit chargeWhat the high income charge takes, and the pension that clears it. 2026-27

Construction

CIS deductionsDeduction on a construction invoice, split from materials. 2026-27

In progress

Section 24 property relief
Salary sacrifice comparison
Estimates, not advice. Check anything that matters with HMRC or an accountant.