Mortgage calculator

Work out your monthly mortgage repayments in seconds. Enter your property price, deposit, interest rate and term to see a full cost breakdown.

Monthly repayment figure
Total interest over the term
Loan-to-value (LTV) ratio
Currency auto-set by location

Property price

Deposit

Annual interest rate (%)

Mortgage term (years)

Please fill in all required fields.

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How mortgage repayments are calculated

A repayment mortgage spreads your loan amount plus interest across the full term. In the early years, the majority of each monthly payment covers interest; as the outstanding balance reduces, progressively more goes towards the capital. This is called amortisation. By the final payment, the loan is fully cleared.

You can verify any individual figure using our online calculator.

Understanding loan-to-value (LTV)

LTV is the percentage of the property value you are borrowing. A lower LTV signals less risk to a lender and typically unlocks better interest rates. Most lenders price their products in bands:

LTV band	Typical outcome
Below 60%	Best available rates, widest product choice
60–75%	Competitive rates, most high-street lenders
75–85%	Standard rates, good range of products
85–90%	Limited products, rates rise noticeably
Above 90%	Specialist lenders; government schemes may apply

What this calculator does not include

The figures shown are repayment and interest estimates only. The following costs are not included:

Arrangement and product fees (typically £999–£1,999)
Valuation and survey fees
Solicitor and conveyancing costs
Stamp duty land tax (SDLT)
Buildings and contents insurance
Overpayment charges or early repayment fees
Interest-only products (this calculator assumes a full repayment mortgage)

Results are for illustrative purposes only and do not constitute financial advice. Always consult a qualified mortgage adviser before making any financial decision.

Frequently asked questions

How is a monthly mortgage payment calculated?

Using the standard amortisation formula: the monthly payment accounts for both the interest on the outstanding balance and a portion of the capital, so the balance reduces to zero at the end of the term. The formula is: M = P × [r(1+r)ⁿ] / [(1+r)ⁿ−1], where P is the loan, r is the monthly interest rate, and n is the number of payments.

What is a good LTV ratio in the UK?

Below 75% is generally considered strong and unlocks the most competitive fixed rates. First-time buyers often start at 85–95% LTV, which is normal but comes with higher rates and fewer product options.

What interest rate should I enter?

Use the rate from your mortgage offer or the current rate your lender is quoting. If you are comparing scenarios, try 3%, 4%, and 5% to see how sensitive your repayments are to rate changes — even a 1% difference has a significant effect over a 25-year term.

Does this include mortgage fees and stamp duty?

No. The calculator shows repayments and interest only. Arrangement fees, solicitor costs, and stamp duty should be budgeted separately — these can add several thousand pounds to the total cost of buying.

What is the difference between a repayment and interest-only mortgage?

A repayment mortgage pays off both the interest and the loan balance over the term — you own the property outright at the end. An interest-only mortgage only covers the interest each month; you still owe the full loan at the end and need a separate repayment vehicle (such as an investment or savings plan).

How does the mortgage term affect my monthly payment?

A longer term reduces monthly payments but significantly increases total interest paid. For example, a £200,000 loan at 4.5% over 25 years costs roughly £44,000 more in interest than the same loan over 20 years. Most lenders require the mortgage to end before age 70–75 — use our age calculator to check how your age affects the maximum term available.

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