UK Mortgage Calculator

This calculator uses the standard repayment mortgage formula. It converts the annual interest rate into a monthly rate, converts the term into months and calculates the fixed monthly repayment needed to clear the loan by the end of the term.

Each monthly payment includes interest and capital repayment. At the start, interest is a larger part of the payment because the outstanding balance is high. Later, more of the same payment reduces the balance. The Bank of England Bank Rate is not your mortgage rate, but it influences lender funding costs, swap rates and the wider interest-rate environment.

Use the result as a practical planning estimate for loan amount, interest rate, loan term, monthly repayment, total repayment, total interest. The calculator is designed to make the main moving parts visible immediately, so it is most useful when you want to compare scenarios, sense-check a decision, or understand why one input changes the final result.

Before relying on the number, check whether your situation includes anything outside the calculator scope. Common examples are local rules, provider fees, payroll timing, special reliefs, bank holidays, tariff changes, exchange-rate markups, unusual tax codes, or personal circumstances that need official guidance or professional advice.

To make the estimate more accurate, use figures from the most recent bill, payslip, lender quote, receipt, official notice or provider screen you have. Rounded inputs are fine for quick comparisons, but precise inputs are better when you are deciding whether something is affordable or comparing two similar options.

Re-run the calculator whenever a key assumption changes, such as a new rate, different term, changed salary, updated threshold, extra fee, altered usage pattern or different date range. Keeping those assumptions fresh is often more useful than trying to make one calculation perfect.

If you are using the result for a formal decision, keep a note of the inputs you used and the date of the calculation. That makes it easier to compare the estimate with a later quote, bill, payslip or official calculation.