Use these calculator templates to help you navigate your loans, budgets, net worth, and more. The tutorial shows how to build an amortization schedule in Excel to detail periodic payments on an amortizing loan or mortgage.Looking for a flexible free downloadable mortgage calculator built in Excel? Try this free feature-rich mortgage calculator today! This Excel spreadsheet makes it easy to view the amortization of a home loan with optional extra monthly payments. This spreadsheet-based calculator creates an amortization schedule for a fixed-rate loan, with optional extra payments. In this tutorial we will see how to create an amortization schedule for a fixed-rate loan using Microsoft Excel and other spreadsheets. The rounding option is for comparison with other calculators that do not round the payment or interest. Fill in the "Period" column. Fill in the column titled "Period" with your payment dates.