This Microsoft Excel template illustrates how to create a loan amortization schedule, as well as dealing with additional payments and variable interest rates. 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. Open Excel and select "Loan Amortization Schedule" from the template gallery. An amortization schedule is a table format that lists periodic payments on a loan or mortgage over a period of time. What is an Amortization Schedule? PMT (Payment Function): It calculates the fixed monthly payment for a loan based on the interest rate, loan term, and loan amount.