Early Payoff Calculator. Determine the additional monthly payment amount needed to pay off the loan sooner.Prepayment Savings Calculator. Free mortgage payoff calculator to evaluate options to pay off a mortgage earlier, such as extra payments, bi-weekly payments, or paying back altogether. The mortgage payoff calculator helps you find out. Use our free mortgage calculator to easily estimate your monthly payment. See which type of mortgage is right for you and how much house you can afford. Yes, you can make extra payments to pay down your loan, or pay off your loan in full. There is never a fee for making an additional payment. Use our extra payment calculator to see the potential impact an additional payment will have on your long-term finances.