Mortgage Calculator

Free mortgage calculator

Enter your loan amount, annual interest rate and term in years to estimate your monthly mortgage payment, the total interest you'll pay, and the total cost of the loan. Uses the standard amortization formula.

How to use the mortgage calculator

1. Enter the loan amount — the home price minus your down payment.
2. Enter the annual interest rate from your lender's quote.
3. Enter the term in years (commonly 15, 20 or 30).
4. Click Calculate to see your monthly payment, total interest and total cost.

How a mortgage payment works

A mortgage is an amortized loan: you pay the same amount each month, split between interest and principal. Early payments are mostly interest; later payments are mostly principal. The monthly payment uses the standard amortization formula:

M = P × r × (1 + r)ⁿ ÷ ((1 + r)ⁿ − 1)

where P is the loan amount, r is the monthly interest rate and n is the number of monthly payments (years × 12).

Worked example

A $300,000 loan at 6.5% over 30 years gives a monthly payment of about $1,896 (principal & interest). Over 30 years that's roughly $682,000 — meaning about $382,000 in interest. Shortening the term to 15 years raises the payment but slashes total interest dramatically.

What this calculator does and doesn't include

• It shows principal and interest only (the "P&I" part of your payment).
• It does not include property tax, homeowners insurance, HOA fees or PMI — add those separately for a full monthly cost.
• Making one extra payment a year, or rounding the payment up, can shave years off a 30-year mortgage.

Frequently asked questions