Download Microsoft Excel Mortgage Calculator Spreadsheet: XLSX Excel Loan Amortization Schedule Template With Extra Payments. This tutorial will teach you how to create a mortgage calculator and amortization schedule in Microsoft Excel.This spreadsheet is an allinone home mortgage calculator. It lets you analyze a fixed or variable rate home mortgage. Mortgage amortization is the process of paying down your mortgage over the course of your term. An amortization schedule shows how those payments are applied. Mortgage Amortization Schedule Example. Mortgage lenders use amortization tables to map out the schedule of loan repayment. Question: Create a Mortgage Payment Calculator with Amortization Table via Excel following the following instructions: 1. How do you calculate amortization?