Mortgage Calculator

What is a mortgage calculator?

A mortgage calculator estimates the monthly payment on a home loan so you can judge how much house you can afford before you make an offer. It is based on the amount you actually borrow — the home price minus your down payment — along with the interest rate and the length of the loan.

How the payment is calculated

The monthly principal-and-interest payment uses the amortization formula P × r × (1 + r)ⁿ / ((1 + r)ⁿ − 1), where P is the financed amount, r is the monthly rate and n is the number of monthly payments. A larger down payment lowers P, while a longer term spreads the balance over more payments, reducing each one but increasing total interest.

How to use this calculator

Enter the home price, your down payment, the annual interest rate and the term in years, then press Calculate. You will see the monthly principal-and-interest payment, the amount financed and the total interest paid over the life of the mortgage.

Tips for home buyers

Remember that a real mortgage payment often also includes property tax, home insurance and sometimes mortgage insurance, so budget above the principal-and-interest figure. Even a small drop in the interest rate, or a slightly larger down payment, can save many thousands over a 25- or 30-year term.