This mortgage payoff calculator is designed to help you understand the impact of making additional payments on your mortgage. This mortgage calculator will help you estimate your monthly mortgage payments based on the home price, down payment, loan term, and interest rate.Do you need to focus on building up your emergency reserve before you start making extra payments on your debt?) Consolidation. 1) Call the mortgage department and request an official principal payoff letter. In this lesson we'll learn how to calculate the number of periods for a loan. If you'd like to refinance your auto loan, let Clark County Credit Union help. Answers to frequently asked questions about international student financial aid at Clark University. Additional payment options are listed here for your convenience. HELOC loans normally come as a variable rate loan and do not normally require borrowers to pay closing costs. So, if you chose to use both and make two extra payments, you would pay off your loan even faster. 2.