This Microsoft Excel template illustrates how to create a loan amortization schedule, as well as dealing with additional payments and variable interest rates. Use the form below to calculate.Enter your loan information. This example teaches you how to create a loan amortization schedule in Excel. 1. We use the PMT function to calculate the monthly payment on a loan. Our auto loan payment calculator can help estimate the monthly payments for your next vehicle. The most powerful auto loan calculator on the market from Kelley Blue Book, the most trusted name in the automotive world.