The positive side of mortgage calculators is the ability to make rough comparisons among various scenarios. Plugging different numbers into a calculator can give borrowers good insight into the interplay between the cost of the home, the down payment, the interest rate, the length of the loan and the monthly payment. However, it’s important to make your final decisions based on conversations with your lender which, unlike the mechanical mortgage calculator, will take into account the exact characteristics of your loan, such as whether taxes and insurance are included in the monthly payments, whether you have an ARM or hybrid loan. Mortgage calculators can be useful and educational when used in conjunction with discussions with your lender.