Loan Amortization Formula ; 1. This Microsoft Excel template illustrates how to create a loan amortization schedule, as well as dealing with additional payments and variable interest rates.Visualize your loan payments and amortization schedule with our SBA 7(a) business loan calculator. Paying off your car loan early allows you to get back what you would've paid in interest. A section 179 expense deduction; Amortization of costs during that tax year.