Finance & Money
Rates & guidance reviewed
Planning a home purchase in the UK starts with understanding what you can afford each month. Our free UK mortgage calculator estimates your monthly repayment based on the loan amount, interest rate and mortgage term — all calculated in your browser with no data stored or sent to a server.
Whether you are a first-time buyer comparing offers or remortgaging at the end of a fixed deal, this tool uses the standard capital-and-interest repayment formula used by UK lenders. Results are estimates only; your actual payments depend on fees, product type and the lender’s underwriting.
Enter property price and deposit to see loan-to-value (LTV), or type the loan amount directly. Try the worked examples below (for example £250,000 at 4.5% over 25 years), then copy your results to compare quotes. Pair this with our stamp duty, Council Tax band and take-home pay calculators for a fuller picture of monthly housing costs.
Repayment formula (capital & interest) · guidance rates only
Full purchase price
Cash you put down
Loan amount
£250,000
Price minus deposit
e.g. 4.5 from your quote
Commonly 25 or 30
Estimate only for a repayment (capital and interest) mortgage. Does not include arrangement fees, insurance, overpayments or interest-only products. Always confirm with a broker or lender.
Static sample calculations you can read without using the form. Figures match this tool's maths — always re-run with your own numbers for a personal estimate.
Common repayment scenario — matches a £312,500 purchase with a £62,500 deposit (80% LTV).
Inputs
Results
Assumes a fixed rate for the full term and level monthly capital-and-interest payments. Not a lender offer.
Longer term lowers the monthly payment but raises total interest.
Inputs
Results
Higher rate and larger loan — useful stress-test style comparison.
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Results
Mid-size loan with a longer term for monthly payment planning.
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Results
Three inputs drive a standard repayment mortgage: how much you borrow, the interest rate, and how long you spread the loan. A larger deposit lowers the loan and often improves the rates lenders offer because loan-to-value (LTV) is lower. Extending the term reduces the monthly payment but usually increases total interest paid over the life of the mortgage.
UK deals are often fixed for two or five years, then revert to a (typically higher) standard variable or reversion rate. This calculator models a single constant rate for the full term — useful for comparing quotes, but not a full remortgage timeline. Always read the APRC and product features on the lender’s illustration.
Stress tests, credit history, income multiples and affordability assessments still decide whether you can borrow. Use this tool for planning, then speak to a broker or lender for a Decision in Principle.
For a repayment (capital and interest) mortgage, lenders use a standard amortisation formula. With loan P, monthly interest rate r (annual rate ÷ 12), and n months (years × 12), the monthly payment is M = P × [r(1+r)^n] ÷ [(1+r)^n − 1]. If the rate is 0%, the payment is simply P ÷ n.
Example: a £250,000 loan at 4.5% over 25 years has r = 0.045 ÷ 12 and n = 300, giving about £1,389.58 per month with this tool. Changing the rate by 0.5 percentage points or the term by five years can move the payment by tens or hundreds of pounds — try both in the calculator above.
This is the same structure used for most UK residential repayment products. It does not replace a Mortgage Illustration, which includes fees, product features and the APRC.
Most residential buyers use a repayment mortgage: each payment covers interest and reduces the capital. Interest-only products charge interest only; you still owe the original loan at the end unless you have a separate repayment vehicle. This calculator is for repayment mortgages only.
Monthly mortgage cost is only part of the picture. Upfront, many buyers also face stamp duty (SDLT, LBTT or LTT), legal fees and survey costs. Ongoing, Council Tax, buildings insurance and maintenance matter for affordability checks.
Use our free stamp duty calculator for purchase tax by nation, the Council Tax band helper for annual bills from Band D, and the take-home pay calculator to see what salary supports a given budget after Income Tax and National Insurance.
Always confirm rates, bands and eligibility on official pages. Our tools are simplified estimators for guidance only.