Mortgage Calculator
This free mortgage calculator estimates your monthly payment from the home price, down payment, loan term, and interest rate, plus optional property tax, home insurance, and HOA fees. It also shows your total interest paid, total cost of the loan, and payoff date. Nothing you enter is sent anywhere or stored.
How to Use It
- Enter the home price and your down payment.
- Choose a loan term and enter the interest rate.
- Optionally add property tax, home insurance, and HOA fees.
- Your monthly payment and loan summary appear instantly as you type.
How It Works
Monthly principal and interest is calculated with the standard mortgage amortization formula, which spreads the loan amount (home price minus down payment) evenly over every monthly payment so that, by the final payment, both the principal and interest are fully paid off. At a fixed interest rate, this means early payments are mostly interest and later payments are mostly principal, even though the total payment amount stays the same throughout the loan.
Formulas
loan amount = home price − down payment
monthly P&I = loan amount × [r(1 + r)^n] ÷ [(1 + r)^n − 1], where r = annual rate ÷ 12 ÷ 100 and n = number of monthly payments
Property tax and home insurance are usually paid annually or semi-annually, but lenders typically collect a share of each with your monthly payment (an escrow account) rather than billing you separately, so this calculator splits your entered annual amounts evenly across 12 months to match. HOA fees, when they apply, are already a monthly charge.
| Included in the estimate | Not included |
|---|---|
| Principal & interest | PMI (private mortgage insurance) |
| Property tax | Utilities |
| Home insurance | General home maintenance |
| HOA fees | Closing costs |
A worked example: a $400,000 home with a $80,000 (20%) down payment leaves a $320,000 loan. At a 6.5% annual rate over a 30-year term, that comes to a monthly principal-and-interest payment of $2,022.62, and over all 360 payments, a total of $408,142.36 in interest, on top of the original $320,000 borrowed. Property tax, home insurance, and HOA fees (if you enter them) are added on top of that principal-and-interest figure, not folded into the amortization math itself.
For the full derivation of the amortization formula, why early payments are mostly interest, and exactly how much an extra monthly payment toward principal saves, see our guide, How Mortgage Amortization Actually Works.
Everything runs client-side in your browser. No numbers you enter are sent anywhere or stored.
Frequently Asked Questions
What does the monthly payment estimate include?
It includes principal and interest, plus property tax, home insurance, and HOA fees if you enter them. It does not include PMI (private mortgage insurance). See the next question for why. Utilities and general home maintenance aren't part of a mortgage payment at all, so they're left out too.
What is PMI, and why isn't it calculated here?
PMI is insurance most lenders require when your down payment is under 20% of the home price, protecting the lender (not you) if you default. It typically drops off automatically once you reach 20% equity, an amortization-dependent cutoff that varies by lender, not a fixed monthly amount. Because the actual rate and cutoff depend on your specific lender, this calculator leaves it out rather than showing a plausible-looking number that might not match your real quote. Ask your lender directly for a PMI estimate if your down payment is under 20%.
How do extra principal payments affect total interest?
Any payment beyond the required monthly amount goes directly toward the loan's principal balance, which reduces the interest charged in every future month for the rest of the loan, so extra payments made earlier in the loan save more total interest than the same extra payment made later. This calculator shows the standard payment schedule; it doesn't model extra payments. See our guide, How Mortgage Amortization Actually Works, for a full worked example of exactly how much an extra monthly payment can save.
How much does choosing a 15-year term instead of a 30-year term change things?
A shorter term raises the required monthly payment but sharply cuts total interest, since less time means less balance sitting around accruing interest. On a $320,000 loan at 6.5%, a 30-year term runs $2,022.62/month with $408,142.36 total interest, while a 15-year term runs $2,787.54/month, about $765 more, but only $181,757.84 total interest, less than half. The shorter term costs more per month but far less overall.
Does a bigger down payment always help?
It reduces your loan amount, which lowers both your monthly payment and total interest, and a down payment of 20% or more also typically avoids PMI (see below). Beyond that, whether to put more cash toward a down payment versus keeping it liquid depends on your own finances. It's not something this calculator can answer generically, since it depends on your interest rate, other debts, and financial cushion.
Why does the same interest rate produce such a different total cost over 15 vs. 30 years?
Interest is charged on whatever balance remains each month, and a 30-year term simply leaves a balance outstanding for twice as long, giving interest twice as many months to accrue against it. It isn't that the rate itself changes. It's that a longer term means more total months of interest charges, even though each individual month's rate is identical.