The tutorial shows how to build an amortization schedule in Excel to detail periodic payments on an amortizing loan or mortgage. This Microsoft Excel template illustrates how to create a loan amortization schedule, as well as dealing with additional payments and variable interest rates.Variable Interest Rate. The module can accommodate both fixed rate and variable rate loans via a simple drop-down. You can create an Excel amortization table with changing interest rates. Here's how you can build it. To use our amortization calculator, type in a dollar figure under "Loan amount. This calculator will help you figure out your regular loan payments and it will also create a detailed schedule of payments. In most cases the version will max out before the loan matures. In some cases the amortization can have a bigger impact on the monthly payment than the actual interest rate of the commercial loan.