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Mortgage Calculator

Estimate the monthly repayment on a UK mortgage. Enter the property price, your deposit, an interest rate and the term to see the payment, the loan amount and the total interest over the life of the mortgage.

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Estimate the monthly repayment and total interest on a repayment mortgage.

How a repayment mortgage works

On a repayment mortgage, each monthly payment covers the interest for that month and chips away at the balance. Early on, most of the payment is interest; over time more of it reduces the loan, until the mortgage is cleared at the end of the term.

How deposit and term change the cost

A larger deposit means a smaller loan and usually access to lower interest rates, which reduces both the monthly payment and the total interest. A longer term lowers the monthly payment but increases the total interest paid over the life of the mortgage.

Loan-to-value and interest rates

Lenders price mortgages by loan-to-value (LTV), which is the loan as a share of the property value. Crossing below an LTV threshold such as 90%, 85% or 75% can unlock a better rate, so a slightly larger deposit sometimes makes a meaningful difference.

Worked examples

Buying at £280,000 with 15% deposit

A £42,000 deposit leaves a £238,000 loan. At 4.5% over 25 years the estimated monthly payment is around £1,323, with a large share of the early payments going on interest.

Shorter term, higher payment

Cutting the term from 25 to 20 years raises the monthly payment but reduces the total interest, because the balance is cleared sooner.

How we calculate this

The monthly payment uses the standard repayment mortgage formula based on the loan amount, monthly interest rate and number of monthly payments.

The loan amount is the property price minus the deposit entered.

Total interest is the sum of all payments minus the original loan. The estimate assumes a fixed interest rate for the whole term and does not include fees, insurance or rate changes.

Official sources

FAQs

Is this the exact amount I will pay?

No. It is a guide. Your real payment depends on the rate you are offered, any product fees, and whether the rate is fixed or variable for the whole term.

Does it include interest-only mortgages?

No. This estimate is for a capital repayment mortgage. An interest-only payment would be lower but would not reduce the balance.

How much deposit do I need?

Many lenders accept 5% to 10%, but a larger deposit lowers your loan-to-value and can unlock cheaper rates and lower payments.

What rate should I enter?

Use a rate close to current deals for your likely loan-to-value. Trying a range shows how sensitive the payment is to the rate.

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Renting vs Buying a Home

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Buying builds equity and can lower housing costs later in life, but it comes with a large deposit, transaction costs and maintenance responsibility. Renting does not build ownership, but it can be financially sensible when your plans, job or location are still uncertain.

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