Best Mortgage Calculators in the UK
Find the right mortgage calculator for UK home buyers. Compare tools for payments, affordability, stamp duty, and overpayments.
CalculatorZone Editorial Team12 min readPublished Updated
Introduction
Buying a home in the UK requires navigating one of the world's most complex property markets. With the Bank of England base rate influencing mortgage rates and house prices high in many areas, having the right calculators at your fingertips can save you thousands. This guide covers the essential free tools every UK buyer should use before signing anything.
Key Calculators
- Mortgage Repayment Calculator — Uses standard amortisation to show your exact monthly payment, total interest paid, and full repayment schedule over 25 or 30 years: Open the Mortgage Repayment Calculator
- Affordability Calculator — UK lenders typically offer up to 4.5× your gross annual income. This tool shows how much you can borrow based on income and outgoings: Open the Affordability Calculator
- Stamp Duty Calculator — Calculates your SDLT liability across the England and Northern Ireland bands: 0% up to £125k, 2% on £125k–£250k, 5% on £250k–£925k, 10% on £925k–£1.5m, 12% above. First-time buyers pay 0% up to £300k and 5% on £300k–£500k, with no relief above £500k: Open the Stamp Duty Calculator
- Overpayment Savings Calculator — Shows how much interest you save and how many years you shave off by making monthly or lump-sum overpayments: Open the Overpayment Savings Calculator
- Fixed vs Variable Comparison — Compare the total cost of a fixed-rate deal against a tracker or SVR mortgage over the same term: Open the Fixed vs Variable Comparison calculator
Stamp Duty on Example House Prices by Region
The prices below are rounded illustrations, not published averages. The stamp duty column uses the standard England rates from 1 April 2025 with no first-time buyer relief.
| Region | Example House Price | Stamp Duty (no relief) |
|---|---|---|
| London | £525,000 | £16,250 |
| South East | £385,000 | £9,250 |
| Midlands | £255,000 | £2,750 |
| North of England | £190,000 | £1,300 |
| Scotland | £200,000 | Not applicable (Scotland pays LBTT, about £1,100 at this price) |
Tips for UK Mortgage Hunters
Always check the Bank of England base rate before fixing your mortgage — if rates look set to fall, a tracker could save money. HMRC's stamp duty guidance is updated regularly, so cross-check any calculator against the official SDLT calculator on GOV.UK. If you're a first-time buyer, the 4.5x income rule is a starting point, but some lenders go up to 5.5x for high earners. Use the overpayment calculator to model what happens if you pay an extra £100–£200 a month — the lifetime savings can be dramatic.