UK Mortgage Calculator
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.
How the calculation works
We believe numbers should be transparent. Here is the formula behind this calculator.
Worked example
Worked example: a £300,000 home
Examples at common levels
See how the numbers change at typical input levels, using the updated august 2026 rates.
| Scenario | Estimated monthly payment | Yearly repayment | Total interest over the term | Total amount repaid | Loan-to-value (LTV) | Mortgage amount |
|---|---|---|---|---|---|---|
| £250,000 · £50,000 deposit 80% LTV | £1,111.66 | £13,339.98 | £133,499.49 | £333,499.49 | 80.0% | £200,000.00 |
| £300,000 · £60,000 deposit 80% LTV | £1,334.00 | £16,007.98 | £160,199.38 | £400,199.38 | 80.0% | £240,000.00 |
| £400,000 · £80,000 deposit 80% LTV | £1,778.66 | £21,343.97 | £213,599.18 | £533,599.18 | 80.0% | £320,000.00 |
| £350,000 · £35,000 deposit 90% LTV at a higher rate | £1,788.54 | £21,462.42 | £328,872.73 | £643,872.73 | 90.0% | £315,000.00 |
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.
Rates & official sources
Every calculation is based on the official rates and rules published by GOV.UK and HMRC.
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.
How much interest do I pay over the full term?
It depends on the rate, term and type. On a £240,000 repayment mortgage at 4.5% over 25 years you repay roughly £160,000 in interest alone. Shorter terms and overpayments reduce that figure significantly.
Does the monthly payment include home insurance and fees?
No. This calculator covers the capital and interest only. Arrangement fees, valuation fees, buildings insurance and mortgage protection are all separate costs to budget for.
Related calculators
Related guides
New to the topic? Read a plain-English guide on mortgage & property, with worked examples and tips.
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.