Mortgage Payment Calculator — Monthly P&I, Taxes, Insurance & PMI

When you shop for a house, the sticker price is only half the story — what really matters is the full monthly payment that lands in your budget. Most online quotes show only principal and interest (P&I), but the check you actually write each month is bigger. Lenders bundle four things into one escrowed payment that the industry calls PITI: Principal, Interest, Taxes, and Insurance — and on top of that you may owe HOA dues and PMI (private mortgage insurance). This page is about assembling all of those line items into one number, so you can see your true cost of ownership rather than the headline rate.

Start with the principal-and-interest piece, which uses the standard amortization 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 (the annual APR ÷ 12 ÷ 100), and n is the number of payments (loan term in years × 12). P&I is only the foundation, though — the goal here is the stacked total.

Worked example — your monthly payment. Say you finance $320,000 at 6.5% APR for 30 years. Then r = 6.5 ÷ 1200 = 0.00541667 and n = 360. Plugging in:

M = 320,000 × 0.00541667 × (1.00541667)³⁶⁰ ÷ ((1.00541667)³⁶⁰ − 1) ≈ $2,022.62 per month in principal and interest.

That is just the first two letters of PITI. Now stack on the escrowed costs lenders collect with the loan: $4,800/year in property tax works out to $400/month, and $1,500/year in homeowners insurance adds $125/month. If your home sits in a managed community, add HOA dues — say $150/month — and your true payment climbs to roughly $2,697.62/month. Layer in PMI if it applies and the number rises again. Suddenly the payment is more than a third bigger than the P&I figure the listing site quoted you.

PMI appears when your equity is under 20%, typically adding 0.5%–1.5% of the loan per year until you cross that threshold; for how a larger or smaller down payment changes PMI and the equity you start with, see our Down Payment Calculator, which owns that decision in depth. The job of this tool is the breakdown itself — showing how P&I, taxes, insurance, HOA, and PMI each contribute to the bottom line.

The most common mistake buyers make is budgeting off the P&I number alone. Taxes and insurance can add 20–35% to your payment, and in high-tax states or HOA communities the gap is even wider. This calculator builds the whole PITI-plus picture so you know the real monthly number before you fall in love with a listing.

This tool provides informational estimates only, not a loan offer or financial advice; your actual rate, payment, taxes, and insurance are set by your lender and local authorities.