Mortgage Repayment Calculator

How mortgage repayments are calculated

A repayment mortgage charges interest on the outstanding balance each month while you also pay down a slice of the capital, using the standard amortisation formula. Early payments are mostly interest; later payments mostly capital. An interest-only mortgage keeps payments lower but the full loan remains due at the end of the term.

Small rate differences compound dramatically: on a £200,000 loan over 25 years, the difference between 4.5% and 5.5% is roughly £115 a month — about £34,000 over the term. Buying a property? Don't forget stamp duty on top of your deposit.