UK Mortgage Calculator

How the payment is calculated

A capital and interest (repayment) mortgage has the same monthly payment for the whole term while the fixed or tracker rate stays the same: a £315,000 loan at 4.5% over 25 years costs £1,750.87 a month and about £210,300 in interest. With an interest-only mortgage you pay just the interest – £1,181.25 a month here – and still owe the full £315,000 at the end, so lenders want a credible repayment plan. Equal capital repayments start higher (£2,231.25) and fall every month.

Stamp duty in 2026

In England and Northern Ireland, Stamp Duty Land Tax is charged in slices: 0% up to £125,000, 2% to £250,000, 5% to £925,000, 10% to £1.5 million and 12% above. On a £350,000 home a home mover pays £7,500. First-time buyers pay nothing up to £300,000 and 5% on the part up to £500,000 – £2,500 on the same home – but get no relief at all above £500,000. Buyers of an additional home pay 5 percentage points more on every slice: £25,000.

Loan-to-value and rates

Lenders price mortgages in LTV bands – typically 60%, 75%, 80%, 85%, 90% and 95%. A 10% deposit puts you in the 90% band; moving down a band, for example to 85%, usually brings a lower rate. Most lenders lend up to about 4.5 times household income, some up to 5 or 5.5 times for higher earners.

Cash needed upfront

Besides the deposit, budget for stamp duty, the lender’s arrangement fee (often £0–£1,999), conveyancing, searches and a survey. The calculator adds them up.

Frequently asked questions