Mortgage Calculator

How this mortgage calculator works

This calculator computes your monthly mortgage payment including principal, interest, property taxes, and homeowners insurance (PITI). If your down payment is below 20%, private mortgage insurance (PMI) is added automatically. The math uses the standard amortization formula — the same one lenders use.

The mortgage payment formula

Monthly payment (P&I) = P × [r(1+r)ⁿ] / [(1+r)ⁿ − 1]

• P = loan amount (home price minus down payment)
• r = monthly interest rate (annual rate ÷ 12)
• n = total payments (years × 12)

Taxes, insurance, and PMI are then divided by 12 and added to get your true monthly cost.

What counts toward your payment

• Principal & interest (P&I) — the core loan repayment
• Property taxes — typically 0.5%–2% of home value per year
• Homeowners insurance — usually $1,000–$2,500/yr
• PMI — required below 20% down, ~0.5%–1% of loan per year
• HOA dues and flood insurance are not included — add them mentally if they apply.

How to lower your payment

• Increase your down payment — every 5% extra drops PMI and lowers the principal
• Improve your credit score — borrowers above 760 get the best rates
• Choose a shorter term — 15-year rates are typically 0.5%–1% lower than 30-year
• Shop multiple lenders — rates vary by 0.25%–0.5% between lenders on the same day