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.This calculator allows you to enter an initial lump-sum extra payment along with extra monthly payments which coincide with your regular monthly payments. NerdWallet's early mortgage payoff calculator figures out how much more you need to pay. Use Allstate's free mortgage payoff calculator to estimate what it might cost to payoff off your mortgage early. Find out how much you need to pay off here. Enter your normal mortgage information at the top of this calculator. You can optionally add your other homeownership expenses in the middle section. In addition, the calculator allows you to input extra payments (under the "Amortization" tab). The original amount financed with your mortgage, not to be confused with the remaining balance or principal balance.