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.Create a printable amortization schedule with dates to see how much principal and interest you'll pay over time. This calculator will help you figure out your regular loan payments and it will also create a detailed schedule of payments. You can create an Excel amortization table with changing interest rates. Here's how you can build it. In some cases the amortization can have a bigger impact on the monthly payment than the actual interest rate of the commercial loan. Estimated interest rate. Use our free loan payment calculator to estimate monthly payments, interest, and repayment timelines. HELOCs are variable-rate loans, which means your interest rate will adjust periodically.