Tiny Mortgage Calculator Version 1 descriptions Tiny Mortgage Calculator 1. 0 is a free Windows application that lets you quickly calculate some essential mortgage-related figures. Simply enter the amount to be financed the interest rate & duration of the loan. After entering those three numbers into the Tiny Mortgage Calculator click on the "Calculate" button & you will immediately see how much you would have to pay monthly & yearly. You will also be able to find out how much you would have to pay in finance charges & what percentage of the principal they would represent. Finally the total cost of the loan will be displayed.