Calculate your monthly mortgage repayments based on property price, deposit, interest rate, and term.
This calculator provides estimates for guidance only. It does not constitute financial advice. Mortgage terms and rates vary by lender. Always consult a qualified mortgage adviser before making financial decisions.
A mortgage is typically the largest financial commitment most people will make. Understanding your monthly repayments before you start house-hunting helps you set a realistic budget and avoid overextending yourself. In the UK, the majority of residential mortgages are repayment mortgages, where each monthly payment covers both interest and a portion of the capital, gradually reducing the outstanding balance to zero by the end of the term. Mortgage interest rates in the UK are influenced by the Bank of England base rate, lender competition, and your loan-to-value (LTV) ratio -- the proportion of the property price you are borrowing. A larger deposit means a lower LTV, which typically qualifies you for better interest rates. Most UK mortgages are offered as fixed-rate deals (commonly 2 or 5 years) or variable-rate trackers. This calculator shows you the monthly payment for a standard repayment mortgage at a given interest rate and term. It also calculates the total amount you will repay over the life of the mortgage and the total interest cost, helping you compare different scenarios -- such as increasing your deposit, choosing a shorter term, or shopping for a lower rate.
To calculate your mortgage repayments: 1. Enter the property price. This is the full purchase price of the home you are buying. 2. Enter your deposit amount. The deposit is the cash you are putting toward the purchase upfront. The calculator subtracts this from the property price to determine your loan amount. 3. Set the interest rate. Enter the annual interest rate offered by your lender. If you are comparing deals, try different rates to see how they affect monthly payments and total interest. 4. Adjust the mortgage term using the slider. UK mortgages typically range from 5 to 40 years, with 25 years being the traditional standard. A shorter term means higher monthly payments but significantly less total interest. A longer term reduces monthly payments but increases the total cost. 5. Review the results. The calculator displays your monthly payment, total repayment over the full term, total interest paid, and the loan amount. The line chart shows the amortisation schedule -- how your balance decreases over time and the split between interest and capital in each year.
The monthly payment for a repayment mortgage is calculated using the standard annuity formula: M = P x [r(1 + r)^n] / [(1 + r)^n - 1] Where M is the monthly payment, P is the principal (loan amount), r is the monthly interest rate (annual rate divided by 12), and n is the total number of monthly payments (term in years multiplied by 12). This formula ensures that each monthly payment is identical throughout the term. In the early years, a larger proportion of each payment goes toward interest. As the outstanding balance decreases, more of each payment is applied to the principal. This shift is visible in the amortisation chart. The total repayment is simply the monthly payment multiplied by the total number of payments. The total interest is the total repayment minus the original loan amount. For example, borrowing GBP 200,000 at 4.5% over 25 years produces a monthly payment of approximately GBP 1,111. Over the full term, you would repay roughly GBP 333,400 -- meaning GBP 133,400 goes to interest alone. Reducing the term to 20 years increases the monthly payment to about GBP 1,265 but saves over GBP 30,000 in total interest.
This calculator assumes a fixed interest rate for the entire mortgage term. In practice, most UK mortgages have an initial fixed or tracker period, after which the rate may change to the lender's standard variable rate (SVR). Overpayments, remortgaging, and rate changes are not modelled here. For personalised mortgage advice, consult a qualified mortgage adviser. The calculator does not include arrangement fees, valuation fees, or solicitor costs.