Mortgage Repayment Calculator
Estimate your monthly mortgage payment and total interest. Compare repayment and interest-only mortgages, and see how rate and term change the cost.
Your mortgage
The annual rate on the deal.
Your results
Monthly payment
£1,376
You borrow
£247,500
90% loan-to-value
Total interest
£165,206
Total repaid
£412,706
If the rate were 1% higher (5.50%), your payment would be about £1,520 a month, which is £144 more.
An estimate for illustration only, not an offer. It assumes one rate for the whole term and excludes fees, insurance and other costs. Your home may be repossessed if you do not keep up repayments on a mortgage.
How the calculation works
Enter the property price, your deposit, the interest rate and the length of the mortgage. The calculator works out the amount you would borrow, your loan-to-value (LTV) ratio and the monthly payment. It also shows what the payment would be if the rate were one percentage point higher, which is a useful test of whether the mortgage would still be affordable if rates rose.
With a repayment mortgage, each payment covers the interest and pays off some of the loan, so the debt is gone at the end of the term. With an interest-only mortgage you pay only the interest each month and still owe the full loan at the end, so you need a separate plan to repay it.
What the figure does not include
The monthly payment is for the mortgage only. It does not include buildings and contents insurance, service charges, ground rent, maintenance, energy bills or council tax. It also assumes the same rate for the whole term, while most real deals are fixed for two to five years and then move to a new rate. Product fees added to the loan, and stamp duty, legal and moving costs, are not included either.
Lenders also set their own affordability rules and will not simply lend whatever a calculator says you can repay. Treat the result as a guide to help you decide what to ask about, not an offer or a quote.
Using the results sensibly
A useful habit is to compare the monthly payment with what you pay now in rent or an existing mortgage, then add a margin for everything above. If a payment is only affordable if rates stay low, that is a warning sign. Remember that your home may be repossessed if you do not keep up repayments on a mortgage or other loan secured on it.
Common questions
What interest rate should I use?
Use the rate on a deal you are considering, or try a few rates either side of today's typical offers. The built-in "+1%" comparison shows how sensitive your payment is to rate changes.
What is the difference between repayment and interest-only?
Repayment mortgages reduce the loan each month and clear it by the end of the term. Interest-only mortgages cost less per month but leave the whole loan outstanding, so you must have a credible way to repay it.
Does this show how much I can borrow?
No. How much you can borrow depends on the lender's affordability checks, your income, existing debts and credit history. A broker or lender can give you a proper assessment.
Related guides
These calculators give estimates based on the figures you enter and the assumptions listed above. They are not financial advice. Your numbers are worked out in your browser and are not sent to us.
This page provides general information only. It is not personalised financial, legal or tax advice, and rules and figures can change. Your situation is unique — please check official sources such as GOV.UK and MoneyHelper, and speak to a qualified, FCA-authorised adviser before making important decisions about your money.