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Estimate monthly payments for a UK repayment or interest-only mortgage. Enter your loan amount, annual interest rate and term to compare payments, total interest and any capital left to repay.
Last reviewed
Estimated monthly payment
£1,389.58
Assuming the interest rate stays unchanged for the whole term.
The headline is your estimated monthly mortgage payment. Annual payment is twelve monthly payments, and total paid adds those payments across the selected term. These are mortgage payments only, not a complete home-ownership budget.
For a repayment mortgage, the first-month split shows how much goes towards interest and how much reduces the loan. As the balance falls, the interest portion usually decreases and more of each payment repays capital.
For interest-only, total paid is the sum of interest payments only. The full original loan is shown separately as capital remaining at end and still needs to be repaid. A lower monthly payment does not mean the debt is being cleared.
For a repayment mortgage, the calculation spreads capital and interest across equal monthly payments. The annual percentage rate you enter is divided by 100 and then by 12 to obtain the monthly rate. The term in years is multiplied by 12 to obtain the number of payments.
The formula is payment = P × r × (1 + r)ⁿ ÷ ((1 + r)ⁿ − 1), where P is the mortgage amount, r the monthly rate and n the number of monthly payments. At 0% interest, payment is simply P ÷ n.
For interest-only, monthly payment = P × r. No capital is repaid through those monthly payments, so the original balance remains due at the end.
£250,000 borrowed over 25 years at an unchanged 4.5% annual rate.
Monthly payments total £416,874.36 and clear the mortgage in this model.
£250,000 borrowed over 25 years at an unchanged 6% annual rate.
Monthly payments total £483,226.05 and clear the mortgage in this model.
£250,000 borrowed over 25 years at an unchanged 4.5% annual rate.
Interest payments total £281,250.00; the original capital must be repaid separately.
The result depends on the following. If any of them do not match your situation, treat the figure as indicative only.
This calculator uses the standard monthly amortisation formula for repayment loans and simple monthly interest on an unchanged balance for interest-only loans. A mathematically equivalent form is used internally to preserve accuracy when the interest rate is very close to zero.
The interest rate is supplied by you, not taken from a lender or a tax-year dataset. Calculations run locally in your browser. Automated tests cover ordinary payments, zero and tiny rates, large and small amounts, invalid inputs and both mortgage types.
The MoneyHelper source below explains the difference between repayment and interest-only mortgages and why an interest-only borrower needs a plan to repay the capital. Always check your lender’s mortgage illustration for the actual payment schedule.
The payment depends on the amount borrowed, interest rate, term and mortgage type. As an illustration, £250,000 at 4.5% over 25 years on repayment costs about £1,389.58 a month in this model. Your lender’s quote may differ.
A higher rate increases the monthly payment and total interest when the loan and term stay the same. Compare the same borrowing at several rates to understand how a rate change could affect your budget.
Repayment payments cover interest and reduce the capital so the loan is cleared at the end of the modelled term. Interest-only payments cover interest alone; you need a separate plan to repay the original loan.
No. Arrangement fees, valuation or legal fees, insurance, service charges and early repayment charges are excluded. If a fee is added to your loan, include it in the mortgage amount to estimate interest on that borrowing, but the calculator does not assess fee rules.
Lenders may calculate interest daily, use different payment dates, apply an initial longer or shorter payment period, round differently or include fees. A deal may also change rate before the mortgage term ends. Check the lender’s illustration and offer.
No. It assumes the scheduled payment is made every month without extra payments. Overpayments can reduce the balance and future interest, but lender limits and early repayment charges need to be considered separately.
Only in this estimate. A fixed or discounted deal may last for less than the full term. Run alternative rate scenarios, and do not treat a total-term estimate at today’s deal rate as a prediction of actual future costs.
For a repayment mortgage, spreading capital repayment over more months usually reduces the monthly payment but increases total interest at the same positive rate. For interest-only, the monthly interest stays the same but more years mean more interest payments.
Please note: Results are estimates for general information only and are not financial, tax or legal advice. Figures depend on the assumptions listed on each page and on your personal circumstances.
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