Mortgage Payment Calculator
Enter a loan amount, rate, and term to see the monthly principal-and-interest payment and the total interest over the life of the loan. The rate starts at the latest Freddie Mac national average and can be changed.
Utility
Estimate a monthly payment
Estimate principal-and-interest payments from the latest published national average. Change the amount, rate, or term to compare scenarios.
Default 7.40% · 2026-10-08
Monthly principal and interest
$2,770
Total interest
$597,027
Input
400,000 · 7.40%
This is a simple fixed-rate calculation using published averages. Taxes, insurance, fees, credit profile, and lender terms are not included.
How it is calculated
The monthly payment uses the standard fixed-rate amortization formula: payment = P × r × (1 + r)^n ÷ ((1 + r)^n − 1), where P is the loan amount, r is the monthly rate (the annual rate divided by 12), and n is the number of monthly payments. Total interest is the payment multiplied by n, minus P. At a zero rate the payment is P divided by n.
A worked example
A $400,000 loan at 6.50% over 30 years has a monthly principal-and-interest payment of about $2,528. Over 360 payments the total interest is about $510,000.
What is not included
Property taxes, homeowners insurance, mortgage insurance, association dues, fees, and points are not included, so a payment quoted by a lender can be higher. Actual rates depend on credit profile, down payment, loan type, and lender.
Where the starting rate comes from
The starting rate is the latest weekly national average from Freddie Mac PMMS for the selected term. It is a market average, not an offer.