Mortgage Calculator
Monthly payment from price, down payment, rate, and term — with taxes, insurance, HOA, total interest over the life of the loan, and what an extra payment saves. Formula and assumptions shown. Informational only, not financial advice.
Want the year-by-year breakdown of principal and interest? Open the Amortization Schedule with these numbers.
How to use this tool
- Enter the home price and your down payment — the loan amount is the difference.
- Set the interest rate and term (30, 20, or 15 years).
- Optionally add yearly property tax, home insurance, and monthly HOA dues to see the full monthly cost.
- Try an extra monthly payment to see the interest and years it saves.
How it works
The principal-and-interest payment uses the standard fixed-rate formula: M = P·r·(1+r)ⁿ ÷ ((1+r)ⁿ − 1), where P is the loan amount, r the monthly rate, and n the number of payments. Taxes, insurance, and HOA are pass-through costs added on top — lenders often collect tax and insurance in escrow.
Assumptions: fixed rate for the full term and on-time payments. Not included: PMI (typically required below 20% down), closing costs, and rate changes on ARMs. Estimates only — your lender's Loan Estimate is the authoritative number. This is not financial advice.
Sources & references
- CFPB — Owning a Home: explore interest rates and loan costs
- Freddie Mac — Primary Mortgage Market Survey (current average rates)
Content last reviewed: July 2026.
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Frequently asked questions
How much house can I afford?
A common starting guideline is keeping total housing costs at or below 28% of gross monthly income, but affordability depends on your debts, savings, and stability. Work the calculator backwards: try prices until the total monthly cost fits your budget with room to spare.
What does an extra $100/month actually do?
On a $300,000 loan at 6.5% for 30 years, roughly $58,000 less interest and payoff about 4 years sooner. Extra payments go entirely to principal, which shrinks every future interest charge — use the extra-payment field to see your own numbers.
Why is my lender's payment quote higher?
Usually escrow (property tax + insurance collected monthly), PMI if your down payment is under 20%, or a slightly different rate/fees. This tool shows P&I plus the costs you enter, and doesn't model PMI.
15-year vs 30-year — how do I compare?
Run both terms: the 15-year payment is higher but total interest is typically less than half. The right answer depends on cash flow and what else the money could do — that's a judgment this calculator informs but can't make.