Mortgage Calculator

How a mortgage payment is calculated

Your monthly mortgage payment has up to four parts, often abbreviated PITI: Principal, Interest, Taxes, and Insurance. The calculator above adds optional HOA dues for condos or planned communities.

The principal & interest formula

We use the standard fixed-rate mortgage formula:

M = P × ( r(1+r)^n ) / ( (1+r)^n − 1 )

P = loan principal (home price − down payment)
r = monthly interest rate (annual rate ÷ 12)
n = number of monthly payments (term in years × 12)

A worked example

Take a $400,000 home with 20% down ($80,000), a 6.5% rate, on a 30-year term. The loan principal is P = $320,000. The monthly rate is r = 6.5% ÷ 12 = 0.0054167, and the number of payments is n = 30 × 12 = 360. Plugging into the formula gives a principal-and-interest payment of about $2,023/month. Over 360 payments that's roughly $728,000 paid in total — meaning about $408,000 of interest on top of the $320,000 borrowed. Add property tax and insurance and the real PITI payment is higher; the calculator above shows the full number live as you drag the sliders.

2026 rate context

Mortgage rates in 2026 remain meaningfully above the lows of the early 2020s, with the 30-year fixed hovering in the mid-6% range for well-qualified borrowers. Rates move with the bond market and the Federal Reserve's policy path, so they shift week to week — the figures above the calculator are referenced from Freddie Mac's weekly survey. The practical takeaway is timeless: a single percentage point changes your payment by roughly 10–12%, so it pays to compare several lenders and lock when the numbers work, rather than trying to time the market. If rates fall later, refinancing is always an option.

15-year vs 30-year

The term you choose is the biggest lever on total cost after the rate itself. A 15-year loan carries a higher monthly payment but a lower rate and dramatically less interest; a 30-year keeps the monthly payment affordable but costs far more over its life. On the same $320,000 loan:

The 15-year costs about $630 more per month but saves roughly a quarter-million dollars in interest. If you might refinance instead of committing to the higher payment, model it with our refinance calculator.

How much house can I afford?

A mortgage payment only makes sense relative to your income. Lenders generally want your total monthly debt — including the new mortgage — under about 43% of gross income (the "back-end" DTI), and housing costs alone under roughly 28% (the "front-end" ratio). Rather than reverse-engineer that by hand, start from your income and debts with the house affordability calculator to get a target price, then come back here to price the exact payment.

Why we build by state

Two identical homes at the same price can carry very different monthly costs depending on where they sit. Property-tax rates swing from well under 0.5% to over 2% of value per year, which can mean hundreds of dollars a month in escrow. Transfer taxes and closing costs also differ sharply — some states charge nothing, others several percent of the price. And foreclosure law, insurance costs, and income-tax treatment all vary. That's why each state page is pre-filled with local figures, and why we maintain dedicated property-tax and closing-cost calculators so you can see the full picture before you buy.

Methodology & assumptions

• Fixed interest rate over the full loan term — does not model ARMs or rate resets.
• Property tax and insurance are entered as annual amounts and divided by 12.
• Does not include private mortgage insurance (PMI) — typically required when down payment is below 20%.
• Does not include closing costs, origination fees, or points.
• Amortization is calculated month-by-month and aggregated to yearly buckets for the chart.

Frequently asked questions

This tool is for educational purposes only and does not constitute financial advice. Consult a licensed mortgage advisor for decisions specific to your situation.