UK Mortgage Calculator
Know exactly what your mortgage will cost.
Estimate monthly repayments, total interest and loan-to-value in seconds. Free, instant and built for the UK.
Your monthly payment covers both interest and part of the mortgage balance.
A larger deposit generally reduces the amount you need to borrow.
A longer term may reduce monthly payments but increase total interest.
Assumes 4.5% applies for the full term. UK mortgage rates are typically fixed for 2, 3, 5 or 10 years — your monthly repayment can change when a fixed period ends.
How your total repayment splits between the capital you borrow and the interest paid over the term.
On your figures, about £198,580 of the £496,080 total (~40%) would be interest.
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Based on the details you have entered, your monthly repayment is £1,654 on a £297,500 mortgage at 4.50% over 25 years (LTV 85.0%).
Ask about your repayment breakdown, compare scenarios, or explore how deposit, rate or term changes affect the numbers.
Suggested prompts
With a £350,000 property price and a 15% deposit, you would borrow £297,500. At an interest rate of 4.50% over 25 years, your estimated repayment would be approximately £1,654 per month.
Educational observations calculated from your inputs. Not financial advice.
Based on these inputs, your deposit of £52,500 represents 15.0% of the property's value, so you would borrow £297,500.
Mortgage products are often grouped into Loan-to-Value bands. Rates and eligibility vary by lender and market conditions. In this scenario, reducing the LTV from 85.0% to 80% would require an additional deposit of approximately £17,500.
In this scenario, approximately 40% of the total repayment (£496,080) would be interest — around £198,580.
If all other assumptions remain unchanged, adding £10,000 to your deposit would reduce the estimated monthly repayment by about £56 and reduce total interest over the term by approximately £6,675. This illustration keeps the same interest rate, term and mortgage type, and does not account for lender-specific products, fees or eligibility.
Reducing the term from 25 to 20 years would increase the estimated monthly repayment by approximately £229 but reduce total interest by approximately £44,369, assuming the same mortgage amount and interest rate. This illustration does not account for lender-specific products, fees or eligibility.
Explore your options
Calculated comparisons against alternative scenarios. Illustrative only — not financial advice.
This example assumes your deposit increases by £10,000 while everything else stays the same.
- Monthly repayment−£56(−3.4%)Baseline £1,654£1,598
- Total interest−£6,675(−3.4%)Baseline £198,580£191,906
- Total repayment−£16,675(−3.4%)Baseline £496,080£479,406
- Loan-to-Value−2.9%(−3.4%)Baseline 85.0%82.1%
What we kept the same
- Same interest rate
- Same mortgage term
- Same mortgage type
This example assumes a mortgage term that is 5 years shorter while everything else stays the same.
- Monthly repayment+£229(+13.8%)Baseline £1,654£1,882
- Total interest−£44,369(−22.3%)Baseline £198,580£154,212
- Total repayment−£44,369(−8.9%)Baseline £496,080£451,712
What we kept the same
- Same mortgage amount
- Same interest rate
- Same mortgage type
This example assumes a mortgage term that is 5 years longer while everything else stays the same.
- Monthly repayment−£146(−8.8%)Baseline £1,654£1,507
- Total interest+£46,579(+23.5%)Baseline £198,580£245,160
- Total repayment+£46,579(+9.4%)Baseline £496,080£542,660
What we kept the same
- Same mortgage amount
- Same interest rate
- Same mortgage type
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Capital vs interest paid each year
Your monthly repayment stays roughly constant throughout the term. In the early years, a larger share of each payment goes towards interest. As the balance falls, the interest portion shrinks and more of each payment goes towards capital.
Worked example from your figures
- Capital repaid£6,591
- Interest paid£13,253
- Capital repaid£11,298
- Interest paid£8,545
- Capital repaid£19,368
- Interest paid£475
Outstanding mortgage balance over time
This line shows how much you would still owe at the end of each year. It starts flat and steepens over time as more of each payment goes to capital.
Worked example from your figures
- Balance remaining£290,909
- Balance remaining£183,732
- Balance remaining£0
Interesting facts
- In year 11, the amount of capital repaid (£10,327) first exceeds the interest paid (£9,516) within a single year.
- By the end of year 16, the outstanding balance falls to £146,627 — around 51% of the original mortgage has been repaid.
- Over the full 25-year term, approximately 40% of the total amount paid (£496,080) would be interest — around £198,580.
How it works
The building blocks behind every mortgage calculation.
Mortgage principal
The amount you actually borrow — the property price minus your deposit.
Interest rate
The annual cost of borrowing, expressed as a percentage. We convert this to a monthly rate to work out each payment.
Mortgage term
How long you take to repay the mortgage, in years. Longer terms reduce the monthly payment but increase the total interest paid.
Repayment mortgage
Each month you repay interest plus a slice of the capital, so the balance falls to zero by the end of the term.
Interest-only mortgage
You only pay interest each month. The full capital is still owed at the end of the term and must be repaid separately.
Loan-to-Value (LTV)
The percentage of the property price funded by the mortgage. A lower LTV usually unlocks better rates.
Frequently asked questions
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Disclaimer. This calculator provides estimates for general information only. It does not constitute financial advice, a mortgage offer or confirmation of affordability. Actual repayments and eligibility may differ depending on the lender, product, fees and personal circumstances. Consider obtaining advice from a qualified mortgage adviser.