The tutorial shows how to build an amortization schedule in Excel to detail periodic payments on an amortizing loan or mortgage. 13, Payment number, Payment date, Beginning balance, Scheduled payment, Extra payment, TotalI'm looking for a Biweekly Loan Amortization Schedule that will allow me to input various additional payments depending on ability. This spreadsheet creates an amortization schedule for a fixed-rate loan, with optional extra payments. Create a Loan Amortization Schedule in Excel and include optional extra payments. An easy-to-use amortization calculator.