UK Mortgage Calculator

Your monthly repayments while the fixed rate lasts and after it ends, the loan-to-value your deposit gives you, and what overpaying would save. Built for how UK mortgages actually work.

Updated Sep 28, 2026Bank of England Bank Rate 3.75%Runs in your browser, nothing is sent

Your mortgage

£
£
Type
years
Rates
%
standard variable rate
%
£
£/ mo
Monthly repayment
£0

Loan-to-value
0%
If you move to the SVR
£0
Total interest
£0
Stress test (+3%)
£0
what lenders check you can afford

Over the term

Ways to pay less

Year by year

YearRateMonthlyInterestCapital repaidBalance

How UK mortgages work

Most UK mortgages start with a fixed rate for two, five or occasionally ten years. When the deal ends, the loan moves to the lender's standard variable rate (SVR), which is usually several points higher. Almost everyone then remortgages to a new deal, either with the same lender (a product transfer) or a new one. The calculator shows both paths: staying on the SVR, and remortgaging at a similar rate.

On a repayment mortgage each monthly payment covers interest and some of the loan, so the debt is cleared by the end of the term. On an interest-only mortgage you pay only the interest and must repay the whole loan at the end from savings, investments or a sale. Lenders now require a credible repayment plan for interest-only.

Loan-to-value and your rate

Loan-to-value (LTV) is the mortgage as a percentage of the property value. Lenders price in bands: the best rates are typically at 60% LTV or lower, with steps at 75%, 80%, 85%, 90% and 95%. Moving into a lower band, for example from 86% to 85%, can cut the rate by a quarter to half a point. The first card below shows how much extra deposit it takes to reach the next band.

How much can you borrow?

Most lenders cap borrowing at about 4 to 4.5 times household income, with some going to 5 or 5.5 for higher earners or certain professions. They also run a stress test on your budget at a higher rate, commonly around 3 points above the initial rate, to check you could still pay if rates rose. The stress figure above shows that payment.

Overpayments

Most fixed-rate deals let you overpay up to 10% of the balance each year without an early repayment charge. Overpaying reduces the balance immediately, so every later month's interest is lower. Beyond the allowance, early repayment charges of 1% to 5% usually apply until the fix ends.

Bank Rate and mortgage rates

Tracker mortgages move directly with the Bank of England Bank Rate. Fixed rates follow expectations for future rates, measured by swap rates, rather than Bank Rate itself, so they can move before the Bank does. Our live rates page shows Bank Rate and its recent history.

Questions people ask

What are the monthly repayments on a £250,000 mortgage?

At 4.5% over 25 years, about £1,390 a month on a repayment basis. Over 35 years it falls to about £1,180, but total interest rises by about £80,000. On interest-only it would be about £938 a month, with the full £250,000 still owed at the end.

What happens when my fixed rate ends?

You move onto the lender's standard variable rate unless you arrange a new deal. SVRs are usually well above fixed rates, so start looking three to six months before the fix ends; most lenders let you lock in a new rate that far ahead.

Is a longer mortgage term a good idea?

It lowers the monthly payment and can help you pass affordability checks, but you pay interest for longer. You can take a longer term and overpay when you can, which keeps flexibility.

Should I choose a 2-year or 5-year fix?

A 5-year fix gives certainty for longer and fewer remortgage fees. A 2-year fix suits people who expect rates to fall or plan to move soon. Compare the total cost over the period including product fees, not just the rate.

Do I pay stamp duty as well?

Yes, usually, on top of the deposit. See our stamp duty calculator. First-time buyers in England pay nothing on the first £300,000.