This form is furnished to give you a statement of actual settlement costs. Mortgage Payoff Calculator.1) Call the mortgage department and request an official principal payoff letter. It will only be two (2) steps. Request a loan payoff form your mortgage company, wire in them the funds. This calculator allows you to enter an initial lump-sum extra payment along with extra monthly payments which coincide with your regular monthly payments. The mortgage payoff calculator helps you find out. NerdWallet's early mortgage payoff calculator figures out how much more to pay. If you still have five to 10 years of payments, paying a little more each month toward the principal amount will add up to an early payoff. A closing agent(Fla attorney), not an escrow like here in Calif.