Transparency

How we calculate

Accuracy is the whole point. Every rate below is taken directly from the official authority, dated, and covered by an automated test suite that checks our figures against the government calculators. If a Budget changes a rate, we update one file and re-run the tests.

Mortgage affordability

We estimate borrowing as income × multiple (default of 4.5×, adjustable 4–5.5×), reduced for committed monthly spending. We then apply an FCA-style stress test, re-checking the payment at your rate plus a margin (default 1.0%).

The Bank of England limits lenders to advancing no more than 15% of new mortgages at 4.5x income or above — a portfolio rule, not a hard per-borrower cap. Source: FCA interest-rate stress-test rule.

Take-home pay (2026/27)

The personal allowance is £12,570, reduced by £1 for every £2 of income above £100,000 (source). Income tax bands below are in taxable income — what's left after your allowance. National Insurance (Class 1 employee) is 8% between £12,570 and £50,270, then 2% above (HMRC, verified 2026-07-12).

Income tax bands

GOV.UK · mygov.scot · verified 2026-07-12

England, Wales & Northern Ireland

Taxable income fromBandRate
£0Basic rate20%
£37,700Higher rate40%
£125,140Additional rate45%

Scotland

Taxable income fromBandRate
£0Starter rate19%
£3,967Scottish basic rate20%
£16,956Intermediate rate21%
£31,092Higher rate42%
£62,430Advanced rate45%
£125,140Top rate48%

Student loan repayment thresholds

GOV.UK · 2026/27
PlanThresholdRate above it
Plan 1 (pre-2012)£26,9009%
Plan 2 (2012–2023, England & Wales)£29,3859%
Plan 4 (Scotland)£33,7959%
Plan 5 (2023+, England & Wales)£25,0009%
Postgraduate loan£21,0006%

Repayments are collected on the same earnings basis as National Insurance, so salary sacrifice reduces them. A postgraduate loan repays alongside (not instead of) an undergraduate plan.

Retirement forecast

Projections run in today's money: the growth rate (default 3%, adjustable) is applied after inflation, with monthly compounding. At retirement the pot pays your chosen withdrawal rate (default 4%); the full new state pension of £12,548 a year (£241/week, GOV.UK, verified 2026-07-12) is added from age 67 (state pension age). Retirement income is taxed with the 2026/27 income tax bands above — pension income pays no National Insurance. Simplifications: contributions are level in real terms, and the 25% tax-free lump sum is ignored (conservative). The 4% guideline derives from the Bengen/Trinity studies; UK practitioners often prefer 3–3.5% for early retirement.

Retirement Living Standards (Pensions UK / PLSA)

retirementlivingstandards.org.uk · verified 2026-07-12 · annual after-tax expenditure, assumes you own your home
StandardSingleCouple
Minimum£13,900£22,500
Moderate£32,700£45,400
Comfortable£45,400£62,700

These are spending, not gross income, figures — which is why our calculator compares them against your projected income after tax.

Property-transaction tax (stamp duty)

England & Northern Ireland — Stamp Duty Land Tax (SDLT)

HM Revenue & Customs · effective 2025-04-01 · verified 2026-07-12

Standard rates

Portion of priceRate
£0 – £125,0000%
£125,000 – £250,0002%
£250,000 – £925,0005%
£925,000 – £1,500,00010%
£1,500,000 +12%

First-time buyer (up to £500,000)

Portion of priceRate
£0 – £300,0000%
£300,000 +5%

Additional property

Portion of priceRate
£0 – £125,0005%
£125,000 – £250,0007.0%
£250,000 – £925,00010%
£925,000 – £1,500,00015%
£1,500,000 +17%

Non-UK residents: add 2% to every band.

Scotland — Land & Buildings Transaction Tax (LBTT)

Revenue Scotland · effective 2024-12-05 · verified 2026-07-12

Standard rates

Portion of priceRate
£0 – £145,0000%
£145,000 – £250,0002%
£250,000 – £325,0005%
£325,000 – £750,00010%
£750,000 +12%

First-time buyer

Portion of priceRate
£0 – £175,0000%
£175,000 – £250,0002%
£250,000 – £325,0005%
£325,000 – £750,00010%
£750,000 +12%

Additional dwellings: a flat 8% supplement on the whole price (on properties over £40,000), on top of the standard bands.

Wales — Land Transaction Tax (LTT)

Welsh Revenue Authority · effective 2024-12-11 · verified 2026-07-12

Standard rates

Portion of priceRate
£0 – £225,0000%
£225,000 – £400,0006%
£400,000 – £750,0007.5%
£750,000 – £1,500,00010%
£1,500,000 +12%

Additional property

Portion of priceRate
£0 – £180,0005%
£180,000 – £250,0008.5%
£250,000 – £400,00010%
£400,000 – £750,00012.5%
£750,000 – £1,500,00015%
£1,500,000 +17%

These calculators provide general information, not financial advice. Individual lender criteria and personal circumstances vary — always confirm figures with a qualified adviser, your lender, or the relevant tax authority before acting.