The mortgage payoff calculator helps you find out. This calculator allows you to enter an initial lump-sum extra payment along with extra monthly payments which coincide with your regular monthly payments.Free mortgage payoff calculator to evaluate options to pay off a mortgage earlier, such as extra payments, bi-weekly payments, or paying back altogether. Use this free mortgage calculator with extra payments to quickly estimate your monthly mortgage payment. See how extra payments affect your monthly payment. Use this free Georgia mortgage calculator to estimate your monthly mortgage payments and annual amortization. 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. Show Schedule Table. How much will an extra payment on your mortgage save you overall?