Loan Amortization Schedule with extra payments every period, variable periods in Excel - Office 365 In this accounting lesson, we explain and go through examples of a simple Loan Amortization Schedule with variable (changing) interest rate.This spreadsheet-based calculator creates an amortization schedule for a fixed-rate loan, with optional extra payments. Download a free ARM calculator for Excel that estimates the monthly payments and amortization schedule for an adjustable rate mortgage. 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. You can create an Excel amortization table with changing interest rates. Here's how you can build it. This calculator will help you figure out your regular loan payments and it will also create a detailed schedule of payments. In this trick we want to see an amortization table with a variable rate.