Mortgage Calculator

A mortgage calculator estimates your monthly home loan payment based on the home price, down payment, interest rate, and loan term. Add your property tax and insurance to see the full picture of what you'll pay each month.

How the mortgage payment is calculated

Your monthly principal and interest payment is calculated using the standard fixed-rate amortization formula, which spreads the loan balance evenly across every payment so that it's fully paid off by the end of the term:

M = P × [r(1+r)n] / [(1+r)n − 1]

Where M is the monthly principal & interest payment, P is the loan amount (home price minus down payment), r is the monthly interest rate (annual rate ÷ 12), and n is the total number of monthly payments (loan term in years × 12).

Example: A $400,000 home with a $80,000 (20%) down payment leaves a $320,000 loan. At a 6.5% annual rate over 30 years, principal & interest comes to roughly $2,022/month. Adding $350/month in property tax and $117/month in insurance brings the total estimated payment to about $2,489/month.

What's included in your payment

Lenders often bundle four costs into one monthly payment, sometimes called PITI: Principal (paying down the loan balance), Interest (the lender's charge for borrowing), property Taxes (collected and held in escrow), and home Insurance (also usually escrowed). If you pay HOA dues, add those separately since lenders typically don't collect them.

Tips for lowering your payment

A larger down payment reduces your loan amount and can help you avoid private mortgage insurance (PMI) if you reach 20% equity. Shopping for a lower interest rate, choosing a longer term (which lowers the monthly payment but increases total interest), or making extra principal payments can all reduce what you pay over time — see our Amortization Calculator to visualize the full payoff schedule.

Related Calculators