To use a mortgage payment calculator, all you need are a few details about your loan:

 The total loan amount (also known as the principal). This is calculated by subtracting your down payment from the purchase price of your home plus any closing costs and fees.
 The annual interest rate of your loan, keeping in mind that the annual interest rate is different than the annual percentage rate (APR).
 The term of your loan, or the number of years that you have to pay back the loan. Typically 15 or 30 years.
 The number of payments you make in a year, which is usually 12 (once a month) for mortgage loans.
 The type of loan you are receiving, such as interestonly, fixedrate, or adjustablerate mortgage.
 The current market value of the home.