Loan Interest Calculator

Our loan interest calculator shows how much of each monthly payment goes to interest versus capital. Understanding this helps you see the value of overpaying early in the loan term.

Enter your existing loan balance, current interest rate, and remaining term. The calculator shows how much of each monthly payment goes to interest versus capital, and the total interest remaining on the current loan. This is useful for deciding whether to overpay, switch lender, or simply continue the existing arrangement. Compare the total remaining interest against the interest on a new loan at a lower rate — taking into account any early repayment charge on the existing loan and any arrangement fee on a new one. The APR comparison ensures like-for-like comparison — a lower headline rate with a significant arrangement fee may not be cheaper overall than a slightly higher rate with no fee.