How we calculate
The exact rates, thresholds and formulas behind our calculators, for the 2025/26 tax year. The tables below are generated from the same engine that powers the calculators, so they can't drift.
Every figure here is set from official UK sources. We update it when rates change — usually on 6 April each year and after the Autumn Budget. Results are estimates for guidance only and are not financial advice; always confirm against the official source or a qualified professional.
Income tax — rest of UK (2025/26)
| Band | Rate | Taxable income |
|---|---|---|
| Personal allowance | 0% | £0 – £12,570 |
| Basic rate | 20% | £12,571 – £50,270 |
| Higher rate | 40% | £50,271 – £125,140 |
| Additional rate | 45% | £125,141 and above |
The personal allowance (£12,570) is the amount you can earn tax-free. It is reduced by £1 for every £2 of income above £100,000, reaching £0 at £125,140. Bands above are charged on income after the personal allowance. Source: GOV.UK — Income Tax rates and allowances.
Income tax — Scotland (2025/26)
| Band | Rate | Taxable income |
|---|---|---|
| Personal allowance | 0% | £0 – £12,570 |
| Starter rate | 19% | £12,571 – £15,397 |
| Basic rate | 20% | £15,398 – £27,491 |
| Intermediate rate | 21% | £27,492 – £43,662 |
| Higher rate | 42% | £43,663 – £75,000 |
| Advanced rate | 45% | £75,001 – £125,140 |
| Top rate | 48% | £125,141 and above |
Scotland sets its own income-tax bands for earned income (the personal allowance is UK-wide). Source: GOV.UK — Scottish Income Tax and mygov.scot.
National Insurance (2025/26)
Class 1 employee National Insurance is charged at 8% on earnings between the primary threshold (£12,570) and the upper earnings limit (£50,270), then 2% on earnings above that. We charge NI on pay after any salary-sacrifice pension, which is how sacrifice schemes work. Source: GOV.UK — National Insurance rates.
Student loans (2025/26)
| Plan | Rate | Repaid above |
|---|---|---|
| Plan 1 | 9% | £26,065 |
| Plan 2 | 9% | £28,470 |
| Plan 4 (Scotland) | 9% | £32,745 |
| Plan 5 | 9% | £25,000 |
| Postgraduate | 6% | £21,000 |
Repayments are charged on income above the plan threshold at the rate shown. Source: GOV.UK — Repaying your student loan.
Pension (salary sacrifice)
We model pension contributions as salary sacrifice: the contribution is deducted from gross pay before income tax, National Insurance and student loan are calculated, which is why sacrifice can reduce all three.
Mortgages and loans
Mortgage and loan repayments use the standard amortising-loan formula with monthly compounding. Each month, interest is charged on the outstanding balance and the rest of the payment reduces the principal; the amortisation schedule shows this month by month. Overpayments are applied to the balance, shortening the term and cutting total interest. We assume a fixed rate for the whole term — real mortgages re-fix and may add fees, so treat the figures as estimates.