This calculator will show you the additional monthly payment you will need to make on your current mortgage in order to pay it off within a specified number of years. It will also show you how much interest you will save if you make the calculated additional payment each month, from now until your mortgage is paid off. Special thanks to online subscriber Lyle Crafton for presenting the idea for this calculator. NOTE: Be sure to enter "0" (zero) in any entry boxes that don't apply to you. Also be sure that only numbers and decimal points are entered into the fields (dollar signs and other non-numeric characters will cause a JavaScript error).