Summary
Use this when comparing home-purchase scenarios: amount financed, monthly principal-and-interest payment, and total interest over the full term — before taxes, insurance, or lender fees.
Calculation details
The estimate subtracts the down payment from the home price and assumes equal monthly principal-and-interest payments. Property tax, insurance, association fees, mortgage insurance, and closing costs are excluded. Interpret the payment as P&I only; escrow and fees will raise the amount due to a lender.
Formula
Loan amount = home price − down payment. For monthly rate r and n payments, payment = P × r ÷ [1 − (1 + r)^−n]. At 0%, payment = P ÷ n.
Worked example
$400,000 home with 20% down
A $320,000 mortgage at 6% for 30 years has an estimated principal-and-interest payment of about $1,918.56 per month.
How it works
Enter the purchase price, cash down payment, fixed annual rate, and term in years. Change one input at a time to see how down payment, rate, or term shifts payment and lifetime interest. Full precision is kept until display formatting.
Frequently asked questions
What does this mortgage estimate include?
It includes fixed-rate principal and interest only; property costs and lender fees are excluded.
When is this mortgage most useful?
When comparing fixed-rate offers before taxes, insurance, and HOA fees are layered on.
Are displayed values rounded?
The formula keeps full numeric precision. Values are rounded only when formatted for display.
Can actual results differ?
Yes. Lender underwriting, points, taxes, insurance, and adjustable features can change the payment you are quoted.