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, TotalThis Excel spreadsheet makes it easy to view the amortization of a home loan with optional extra monthly payments. This spreadsheet creates an amortization schedule for a fixed-rate loan, with optional extra payments. Does anyone know how to calculate the principal and interest payments after a one time extra principal payment on a mortgage in excel? This template will help you calculate loan and interest balances, accrued interest at any point in time on loans granted or issued.