UK Mortgage Calculator 2026

With a £270,000 loan (90% LTV) at 5.5% over 25 years on a repayment mortgage, monthly payments are approximately £1,660, and total interest over the full term is roughly £227,000. Change any of the four inputs — price, deposit, rate, or term — to see how your own numbers move.

This calculator applies a simplified income multiple of 4.5x your annual income as an affordable-borrowing guide — a £60,000 income suggests up to £270,000. Real lenders don't use a flat multiple: they run a full affordability assessment based on income, expenses, and the FCA-mandated stress test, so treat the income-multiple figure as a ceiling to sanity-check against, not a guaranteed amount.

LTV (loan-to-value) is your loan as a percentage of the property price — 90% in the £300k/£30k-deposit example above. Lenders reserve their best rates for LTVs of 75% or below, because a bigger deposit means less risk to them. Moving from a 10% deposit to a 25% deposit on the same £300,000 property cuts LTV from 90% to 75% and typically unlocks a meaningfully lower rate.

On the £270,000 loan above at 5.5%, a 25-year term costs about £1,660/month with roughly £227,000 total interest; stretching to 30 years drops the payment to about £1,530/month but raises total interest to roughly £282,000 — about £55,000 more over the life of the loan. Choose the longer term only if you need the lower monthly payment; the shorter term is cheaper overall.

Lender arrangement/product fees, valuation fees, legal and conveyancing costs, and mortgage protection insurance aren't included unless you add them separately. It also doesn't automatically model a rate change after a fixed period ends — re-run the numbers at your expected reversion rate to avoid payment shock.