How to use the mortgage calculator
Enter the home price, your down payment, the interest rate and the loan term. The rate is pre-filled with this week's national average for a 30-year fixed mortgage (6.50%), refreshed automatically from Freddie Mac's Primary Mortgage Market Survey — replace it with the rate from your own lender quote for a more accurate result. Add property tax, homeowners insurance, PMI and HOA dues to see your total monthly housing payment, often called PITI (principal, interest, taxes and insurance).
The mortgage payment formula
The principal-and-interest part of a fixed-rate mortgage payment is calculated with the standard amortization formula:
M = P × r × (1 + r)n ÷ ((1 + r)n − 1)
where P is the loan amount, r is the monthly interest rate (annual rate ÷ 12) and n is the number of monthly payments. In the early years most of each payment goes to interest; over time, more goes to principal. Open the amortization schedule above to see this year by year.
What is PMI and when does it go away?
Private mortgage insurance (PMI) is usually required on conventional loans when you put down less than 20%. It typically costs about 0.3% to 1.5% of the loan amount per year depending on your credit score and down payment. Under the federal Homeowners Protection Act, lenders must automatically cancel PMI when your balance is scheduled to reach 78% of the home's original value, and you can request cancellation at 80%. This calculator removes PMI automatically at the 78% point. FHA loans have a different mortgage insurance premium (MIP) that often lasts for the life of the loan.
How extra payments save money
Every extra dollar you pay goes straight to principal, which reduces the interest charged in every later month. Even $100–$200 extra per month on a 30-year loan can save tens of thousands of dollars and cut years off the loan. Enter an amount in Extra principal payment to see your new payoff date and total interest saved. Check that your loan has no prepayment penalty first.
15-year vs. 30-year mortgage
A 15-year mortgage usually has a lower rate (currently around lower on average) and far less total interest, but a much higher monthly payment. A 30-year loan keeps payments affordable and flexible — you can always pay extra. Switch the term above to compare both.
How much house can I afford?
Many lenders look for a total housing payment below about 28% of gross monthly income and total debt payments below 36%–43% (the debt-to-income ratio). Use our paycheck calculator to see your take-home pay and make sure the payment fits your real budget, including maintenance (often 1%–2% of the home's value per year).
Property tax rates vary widely — from about 0.3% of home value in Hawaii to over 2% in New Jersey and Illinois. Check your county assessor's website for the exact rate.
Frequently asked questions
What is a good mortgage rate right now?
What is included in a mortgage payment?
How much is the payment on a $300,000 mortgage?
Do I need 20% down to buy a house?
Is it better to make extra mortgage payments or invest?
Sources & methodology
This calculator was last reviewed on November 1, 2026. Figures are based on the following official and primary sources:
- Freddie Mac Primary Mortgage Market Survey
- Consumer Financial Protection Bureau – Private mortgage insurance
- Freddie Mac PMMS via FRED; Bank of Canada Valet API
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