This spreadsheet-based calculator creates an amortization schedule for a fixed-rate loan, with optional extra payments. Download a Loan Amortization Table spreadsheet for Excel to create your own amortization schedule, table, or calculator.Free amortization spreadsheet. Note: this spreadsheet is for educational purposes only. 5, A fixed principal loan results in declining payments over the loan period. The tutorial shows how to build an amortization schedule in Excel to detail periodic payments on an amortizing loan or mortgage.