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UK Mortgage Calculator

Updated August 2026 Mortgage & Property GOV.UK guide to mortgages

Enter the property price, your deposit, the interest rate and the mortgage term to see your estimated monthly payment, total interest and loan-to-value (LTV).

Choose between a repayment mortgage (capital and interest) and interest-only to compare the two.

Your details

Results

Estimated monthly payment
£1,334.00
Excludes mortgage insurance and fees
Yearly repayment
£16,007.98
Total interest over the term
£160,199.38
Total amount repaid
£400,199.38
Loan-to-value (LTV)
80.0%
Mortgage amount
£240,000.00

Summary

Property price£300,000.00
Deposit£60,000.00
Mortgage amount£240,000.00
Interest rate4.50%
Term25 years
Loan-to-value80.0%

Outstanding balance over time

240,000
0
£240,000Year 13£0

How the calculation works

We believe numbers should be transparent. Here is the formula behind this calculator.

Monthly repayment = P × r ÷ (1 − (1 + r)^−n), where P = loan, r = monthly rate, n = number of months

Worked example

Worked example: a £300,000 home

Price: £300,000, deposit: £60,000, so the mortgage is £240,000 (80% LTV).
Rate: 4.5% a year, term 25 years.
Monthly repayment ≈ £1,334. Over 25 years you repay ≈ £400,200, of which ≈ £160,200 is interest.

Important assumptions

  • The interest rate stays the same for the whole term. Fixed-rate deals normally reset to the lender’s standard variable rate (SVR) when they end.
  • Excludes arrangement fees, valuation fees, mortgage insurance and other costs.
  • A £0 deposit means a 100% mortgage — be aware lenders rarely offer these.
  • Banks must check affordability, so a “calculated” amount is not a guarantee of borrowing.

Frequently asked questions

How much can I borrow?

Most UK lenders offer roughly 4 to 4.5 times your annual income, and also run an affordability assessment covering your committed spending. See our affordability guide for more.

Repayment or interest-only?

Repayment mortgages pay off the capital each month, so the debt falls to zero by the end of the term. Interest-only mortgages have lower monthly payments but you must repay the full capital at the end, usually via savings or investments.

What is LTV and why does it matter?

LTV is your mortgage as a percentage of the property value. Lower LTV (bigger deposit) usually means cheaper interest rates because the lender carries less risk.

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Related guides

New to the topic? Browse the guides section for plain-English explainers on mortgage & property, including worked examples and tips.

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These calculations are estimates for guidance only and are not professional financial, tax or legal advice. UK rates and rules change, so always verify important figures with official GOV.UK / HMRC information or speak to a qualified professional. See our full disclaimer.