To add a monthly escrow amount to the loan amortization schedule in Excel, you can follow these steps: Insert a new row below the last payment row. Microsoft Excel Mortgage Caculator XLS Worksheet.This spreadsheet-based calculator creates an amortization schedule for a fixed-rate loan, with optional extra payments. This Excel spreadsheet makes it easy to view the amortization of a home loan with optional extra monthly payments. In this tutorial we will see how to create an amortization schedule for a fixed-rate loan using Microsoft Excel and other spreadsheets. This spreadsheet creates an amortization schedule for a fixed-rate loan, with optional extra payments. Use this calculator to generate an estimated amortization schedule for your current mortgage. These calculator templates can help you with your mortgage, loans, budgeting, and more. Set up and maintain clients' Chart of Accounts (COA).