Finance & Money
£250,000 at 4.5% over 25 years works out at about £1,389.58 a month on a repayment mortgage, or £937.50 a month interest-only. Put in your own loan, rate and term below for your estimate.
If you’re planning to buy a home, the first question is usually what you can afford each month. Pop in the loan amount, interest rate and mortgage term, and our free UK mortgage calculator estimates your monthly repayment. It’s all worked out in your browser, so nothing’s stored or sent anywhere.
Whether you’re a first-time buyer comparing offers or remortgaging at the end of a fixed deal, it uses the standard capital-and-interest repayment formula UK lenders use. Here’s the catch: it’s an estimate, and your real payments depend on fees, the product and the lender’s own checks.
Enter the property price and your deposit to see your loan-to-value (LTV), or just type the loan amount. Try the worked examples below (£250,000 at 4.5% over 25 years, say), then copy your results to compare quotes. Our stamp duty, Council Tax band and take-home pay calculators fill in the rest of your monthly housing costs.
For the full explanation, read How stamp duty works when you buy a home in the UK, How UK mortgage payments are calculated, How UK Inheritance Tax is calculated (2026/27), How UK Council Tax bands and bills are calculated or How UK personal loans differ from car finance and student loans.
Bank of England average quoted rates, September 2026
Full purchase price
Cash you put down
Loan amount
£250,000
Price minus deposit
e.g. 4.5 from your quote
Commonly 25 or 30
If the rate stays at 4.5% for the whole term.
| After | Balance owed | Capital repaid | Interest paid |
|---|---|---|---|
| 1 year | £244,461.73 | £5,538.27 | £11,136.70 |
| 2 years | £238,669.02 | £11,330.98 | £22,018.97 |
| 3 years | £232,610.20 | £17,389.80 | £32,635.13 |
| 5 years | £219,644.76 | £30,355.24 | £53,019.63 |
| 10 years | £181,646.19 | £68,353.81 | £98,395.94 |
| 15 years | £134,079.75 | £115,920.25 | £134,204.37 |
| 20 years | £74,536.27 | £175,463.73 | £158,035.76 |
Estimate only. Total interest and the balance table are for a repayment (capital and interest) mortgage at a constant rate. Arrangement fees, insurance and overpayments are not included. Always confirm with a broker or lender.
Examples you can read without entering anything. Use your own figures for a personal estimate.
Common repayment scenario — matches a £312,500 purchase with a £62,500 deposit (80% LTV).
Inputs
Results
Assumes a fixed rate for the full term and level monthly capital-and-interest payments. Not a lender offer.
Longer term lowers the monthly payment but raises total interest.
Inputs
Results
Higher rate and larger loan — useful stress-test style comparison.
Inputs
Results
Mid-size loan with a longer term for monthly payment planning.
Inputs
Results
Mortgage rates have been close to 5% through 2026. The Bank of England’s average quoted rate for a 2-year fixed deal at 75% loan-to-value was 5.13% in September 2026, and 4.98% for a 5-year fix. The table uses 5% so you can see roughly what each loan size costs today, on a repayment mortgage over 25 or 30 years and on interest-only.
So a £70,000 mortgage costs about £409 a month over 25 years, and a £200,000 mortgage about £1,169. Put your own rate in the calculator above, because a 0.5-point difference on a £200,000 loan changes the payment by around £60 a month.
| Loan | Repayment, 25 years | Repayment, 30 years | Interest-only | Total interest, 25 years |
|---|---|---|---|---|
| £50,000 | £292.30 | £268.41 | £208.33 | £37,689 |
| £70,000 | £409.21 | £375.78 | £291.67 | £52,764 |
| £100,000 | £584.59 | £536.82 | £416.67 | £75,377 |
| £150,000 | £876.89 | £805.23 | £625.00 | £113,066 |
| £200,000 | £1,169.18 | £1,073.64 | £833.33 | £150,754 |
| £250,000 | £1,461.48 | £1,342.05 | £1,041.67 | £188,443 |
| £300,000 | £1,753.77 | £1,610.46 | £1,250.00 | £226,131 |
| £400,000 | £2,338.36 | £2,147.29 | £1,666.67 | £301,508 |
On an interest-only mortgage you pay only the interest each month, so the payment is the loan × the yearly rate ÷ 12. On £250,000 at 4.5% that is £937.50 a month, against £1,389.58 on a repayment mortgage. The calculator shows both.
The catch is the end of the term. After 25 years you would have paid £281,250 in interest and still owe the full £250,000, so the total cost is £531,250 against £416,874 on repayment. MoneyHelper explains that lenders want to see a credible plan to repay the loan, such as savings, investments or another property, and that you can’t rely on an inheritance or on house prices rising.
The Bank of England’s Bank Rate is 3.75%. It was held at that level on 17 September 2026 and the next decision is due on 5 November 2026. A tracker mortgage follows Bank Rate plus a margin set by the lender, so its payment changes when Bank Rate does.
A fixed rate is set by the lender for the length of the deal and does not move if Bank Rate changes during it. That is why 2-year fixes averaged 5.13% in September 2026 while Bank Rate was 3.75%. When the deal ends you move to the lender’s standard variable rate unless you switch, and the average quoted standard variable rate was 6.58%.
Judging a mortgage only by the monthly payment. Stretching £250,000 at 4.5% from 25 to 35 years cuts the payment from £1,389.58 to £1,183.14, but adds £80,045 in interest.
Assuming the rate lasts the whole term. After a 2-year fix at 4.5% on £250,000 over 25 years, you would still owe about £238,669. On a new 5-year fix at the September 2026 average of 4.98%, the payment over the 23 years left would be about £1,454. Left on the average standard variable rate of 6.58%, it would be about £1,680, roughly £290 a month more than before.
Comparing rates but not fees. A lower rate with a £999 arrangement fee can cost more than a slightly higher rate with no fee, especially on a small loan. The APRC on the lender’s illustration includes fees, so compare that.
Not testing a rise. On £250,000 over 25 years, each extra percentage point adds about £146 a month at today’s rates. The calculator shows what one point more would cost you.
Under the result, the calculator shows how much of your loan would still be owed after 1, 2, 3 and 5 years and then every 5 years, with the capital and interest paid so far. The table below gives the same figures for common loan sizes at 4.5% over 25 years, if the rate never changed. Only about 12% of the loan is repaid in the first five years, because early payments are mostly interest.
The balance matters most when a fixed deal ends: a new deal or remortgage is worked out on what you still owe over the years left. To check a new payment, choose “Loan amount only”, enter the balance, the new rate and the remaining term. Our mortgage guide shows what a deal ending or overpaying does to the total cost.
| Loan | Monthly payment | After 2 years | After 5 years | After 10 years |
|---|---|---|---|---|
| £150,000 | £833.75 | £143,201 | £131,787 | £108,988 |
| £200,000 | £1,111.66 | £190,935 | £175,716 | £145,317 |
| £300,000 | £1,667.50 | £286,403 | £263,574 | £217,975 |
| £400,000 | £2,223.33 | £381,870 | £351,432 | £290,634 |
Three inputs drive a standard repayment mortgage: how much you borrow, the interest rate, and how long you spread the loan. A larger deposit lowers the loan and often improves the rates lenders offer because loan-to-value (LTV) is lower. Extending the term reduces the monthly payment but usually increases total interest paid over the life of the mortgage.
UK deals are often fixed for two or five years, then revert to a (typically higher) standard variable or reversion rate. This calculator models a single constant rate for the full term — useful for comparing quotes, but not a full remortgage timeline. Always read the APRC and product features on the lender’s illustration.
Stress tests, credit history, income multiples and affordability assessments still decide whether you can borrow. Use this tool for planning, then speak to a broker or lender for a Decision in Principle.
For a repayment (capital and interest) mortgage, lenders use a standard amortisation formula. With loan P, monthly interest rate r (annual rate ÷ 12), and n months (years × 12), the monthly payment is M = P × [r(1+r)^n] ÷ [(1+r)^n − 1]. If the rate is 0%, the payment is simply P ÷ n.
Example: a £250,000 loan at 4.5% over 25 years has r = 0.045 ÷ 12 and n = 300, giving about £1,389.58 per month with this tool. Changing the rate by 0.5 percentage points or the term by five years can move the payment by tens or hundreds of pounds — try both in the calculator above.
This is the same structure used for most UK residential repayment products. It doesn’t replace a Mortgage Illustration, which includes fees, product features and the APRC.
Most residential buyers use a repayment mortgage: each payment covers interest and reduces the capital. Interest-only products charge interest only; you still owe the original loan at the end unless you have a separate repayment vehicle. This calculator is for repayment mortgages only.
Monthly mortgage cost is only part of the picture. Upfront, many buyers also face stamp duty (SDLT, LBTT or LTT), legal fees and survey costs. Ongoing, Council Tax, buildings insurance and maintenance matter for affordability checks.
Use our stamp duty calculator for the tax on your purchase, the Council Tax band helper for the yearly bill, and the take-home pay calculator to see what your salary leaves after Income Tax and National Insurance. All current thresholds are on our 2026/27 rates page.
Check rates, bands and eligibility on these official pages before you rely on a figure.