The tutorial shows how to build an amortization schedule in Excel to detail periodic payments on an amortizing loan or mortgage. This Excel spreadsheet makes it easy to view the amortization of a home loan with optional extra monthly payments.Want to know the impact of "extra payments" on your mortgage? Check out this easy to use Excel mortgage calculator. This spreadsheet creates an amortization schedule for a fixed-rate loan, with optional extra payments. The indepth Watch Me Build is a 25 minute behemoth, showing you how to build a more complex, dynamic amortization table in Excel. This Microsoft Excel template illustrates how to create a loan amortization schedule, as well as dealing with additional payments and variable interest rates. Loan Term (Years), 15. Believe it or not, a loan amortization spreadsheet was the very first Excel template I downloaded from the internet. This is the first of a two-part tutorial on amortization schedules.