SmartRateToolsMortgage Calculator
Enter your loan details below to see your estimated monthly payment, how much interest you'll pay over the life of the loan, and a full breakdown by year.
20.0% down · Loan amount: $320,000
Use your quoted mortgage rate (not APR) for a closer payment estimate.
Estimated Monthly Payment
$2,022.62
Principal & interest only
Loan Amount
$320,000
Total Interest
$408,142
Total Cost
$728,142
Interest / Loan Ratio
128%
What this means
- •With this setup, you'll pay about $408,142 in interest over the life of the loan.
- •A 20.0% down payment keeps your starting loan balance at $320,000.
- •Your principal + interest payment is $2,022.62 monthly before taxes, insurance, and HOA costs.
How does a mortgage work?
A mortgage is a loan you take out to buy a home. Each month, your payment covers two things: principal (the amount you borrowed) and interest (the lender's fee for lending you money). Early in your loan, most of your payment goes toward interest. Over time, more goes toward principal — this is called amortization.
What affects your payment?
- Loan amount — the larger the loan, the higher the payment
- Interest rate — even small differences compound significantly over 30 years
- Loan term — a 15-year mortgage has higher monthly payments but far less total interest
- Down payment — a bigger down payment means a smaller loan
Note: This calculator estimates principal and interest only. Your actual payment may be higher due to property taxes, homeowner's insurance, and PMI (if your down payment is under 20%).
Related reading: How mortgage payments actually work, Amortization, and Principal.