Question 1

How do I calculate my monthly mortgage payment?

Accepted Answer

Enter the Principal amount (the amount you borrow, not the home price), the annual Interest rate in percent and the Loan term in years. The monthly payment, total interest paid and total cost appear instantly; the defaults of 300,000 at 5 percent over 30 years give about 1,610.46 per month.

Question 2

What formula does the mortgage calculator use?

Accepted Answer

It uses the standard fixed-rate amortization formula: payment = P × r × (1 + r)^n ÷ ((1 + r)^n − 1), where P is the principal, r the monthly rate (annual rate ÷ 100 ÷ 12) and n the number of monthly payments. A 0 percent rate simply divides the principal by the number of months.

Question 3

Does the payment include property tax, insurance or PMI?

Accepted Answer

No. The result is principal and interest only. Property taxes, homeowners insurance, PMI, HOA fees and closing costs are not included, so your real monthly housing cost will usually be higher.

Question 4

How do I include a down payment or extra payments?

Accepted Answer

There is no separate down payment field: subtract your down payment from the price and enter the remaining loan amount as the principal. Extra payments, adjustable rates and amortization schedules are not modeled.

Question 5

Is this mortgage calculator financial advice?

Accepted Answer

No. The figures are estimates for comparison only, shown in US dollar format, and real loan offers depend on your lender, fees, rate type and credit. Confirm terms with a lender or a licensed advisor. Your inputs stay in your browser.

Question 6

Why do I see Please enter a valid loan amount, rate, and term?

Accepted Answer

Results only appear when the principal and term are greater than zero and the interest rate is zero or more. Check that no field is empty or negative.