Mortgage Calculator

A mortgage quote is really four numbers, and this mortgage calculator puts them all on one screen: the loan amount left after your down payment, the monthly principal-and-interest installment, the full monthly payment once property tax and home insurance are added, and the total interest you will hand the bank over the life of the loan.

Start with the home price and the down payment — enter it either as a percent of the price (the classic 20%, or the 3–10% many first-time-buyer programs allow) or as an exact amount you have saved. The calculator subtracts it to get the financed principal, then applies the standard annuity formula M = P·r·(1+r)^n / ((1+r)^n − 1), with the monthly rate r equal to the annual rate divided by 12 and n the number of monthly payments across your term.

The principal-and-interest installment is only part of what you actually pay each month, which is why lenders talk about PITI: principal, interest, taxes and insurance. Add your estimated monthly property tax and home insurance in the optional fields and the calculator shows the full monthly payment — the number that has to fit your budget — right next to the bare installment.

Use it to compare a 15-year against a 30-year term, to see how an extra few percent of down payment shrinks both the payment and the total interest, or to sanity-check a lender's estimate before locking a rate. Amounts are plain numbers that work in any currency, and every calculation happens in your browser — nothing is uploaded or stored.