Mortgage Calculator
Estimate your monthly mortgage payment from home price, down payment, rate and term.
A mortgage payment isn't just principal — it's principal and interest blended into one fixed monthly number for the life of the loan. This calculator shows you that number instantly from three inputs: home price, down payment, and rate.
How the monthly payment is calculated
Lenders use the standard amortizing loan formula: M = P × [r(1+r)^n] / [(1+r)^n − 1], where P is the loan amount (home price minus down payment), r is the monthly interest rate (annual rate ÷ 12), and n is the total number of payments (years × 12). Early payments are mostly interest; later payments are mostly principal — the balance just shifts gradually over the loan term.
What this number doesn't include
This calculator gives you principal and interest (P&I) only. Your actual monthly housing cost will usually be higher once you add property taxes, homeowners insurance, and — if your down payment is under 20% — private mortgage insurance (PMI). Lenders often bundle these into an escrow account, so ask for the full "PITI" (principal, interest, taxes, insurance) figure before comparing offers.
Worked example
A $350,000 home with a $70,000 (20%) down payment leaves a $280,000 loan. At 6.75% over 30 years, that's a monthly P&I payment of roughly $1,816 — around $653,760 paid over the full term, of which about $373,760 is interest.
Frequently asked questions
Why is so much of my early payment interest?
Interest is calculated on the remaining balance each month, and early on that balance is at its highest. As you pay down principal, the interest portion shrinks and the principal portion grows — this is called amortization, and it's why paying extra toward principal early saves the most interest over time.
Does a lower rate always mean a lower payment?
Usually, but not always — a 15-year loan at a lower rate can still have a higher monthly payment than a 30-year loan at a higher rate, simply because you're paying it off in half the time. Compare total interest paid, not just the monthly figure, when weighing loan terms.
How much should my down payment be?
20% avoids PMI and lowers your loan amount, but it's not required — many loans allow 3-10% down. A smaller down payment means a bigger loan, a higher payment, and (below 20%) an added PMI cost until you build enough equity.