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Mortgage Calculator
Estimate your monthly mortgage payment, including principal, interest, property tax, home insurance, PMI, and HOA. See total interest paid and your estimated payoff date.
Loan Details
Taxes, insurance & fees (optional)
PMI (private mortgage insurance) is typically required when your down payment is below 20%. This calculator does not estimate a PMI rate for you — enter your lender's quoted amount, or leave at 0 if not applicable.
How the mortgage payment is calculated
The principal & interest portion of your payment uses the standard fixed-rate amortization formula:
M = P × [ r(1+r)n ] / [ (1+r)n − 1 ]
Where P is your loan principal (home price minus down payment), r is your monthly interest rate (annual rate ÷ 12), and n is the total number of monthly payments (loan term in years × 12). This produces a fixed payment that fully amortizes the loan — early payments are mostly interest, and later payments are mostly principal, even though the total payment stays the same every month.
Your total monthly payment (often called PITI) adds property tax and home insurance (converted from annual to monthly), plus PMI and HOA dues if you entered them.
What is PMI and when do I need it?
Private Mortgage Insurance (PMI) is typically required by lenders when your down payment is less than 20% of the home price, to protect the lender if you default. PMI rates vary by lender, credit score, and loan type, so this calculator asks you to enter your lender's quoted monthly PMI amount rather than guessing a rate. PMI is usually removed once you reach 20-22% equity.
Frequently asked questions
Is this calculator accurate?
The principal & interest math uses the exact standard amortization formula used across the mortgage industry, so for a given rate, term, and loan amount, the payment shown will match what any accurate mortgage calculator or lender would quote. What it can't know is your specific lender's fees, exact PMI rate, or final underwritten rate — those come from your Loan Estimate.
Does this include closing costs?
No. This calculator estimates the recurring monthly payment only. Closing costs (origination fees, title insurance, appraisal, etc.) are typically paid once at closing and aren't part of the monthly payment shown here.
Are my numbers uploaded anywhere?
No. Every calculation happens locally in your browser using JavaScript. Your home price, rate, and other figures are never sent to a server.
Why does the amortization chart show interest exceeding principal early on?
With a fixed monthly payment, the interest owed each month is calculated on the current remaining balance — which is highest at the start. So a larger share of your early payments goes to interest, and the principal share grows over time as the balance shrinks. This is normal and identical across all standard fixed-rate amortizing loans.