Use our free UK mortgage calculator to estimate your monthly repayments based on the loan amount, interest rate, and mortgage term. See a full amortisation schedule showing how much of each payment goes to interest versus capital. Supports both repayment and interest-only mortgages. Understanding your mortgage costs is one of the most important steps in buying a home. Our calculator uses the standard annuity formula to give you accurate monthly payment figures. You can also compare different scenarios — for example, what happens if interest rates rise by 1%, or if you overpay each month.