The tutorial shows how to build an amortization schedule in Excel to detail periodic payments on an amortizing loan or mortgage. Loan amortization schedule. 3.4, Enter values, Loan summary. Fill in the "Period" column. Fill in the column titled "Period" with your payment dates. This Excel spreadsheet makes it easy to view the amortization of a home loan with optional extra monthly payments. Does anyone know how to calculate the principal and interest payments after a one time extra principal payment on a mortgage in excel? Include options for extra payments in the loan amortization schedule. Accounting Data Entry Data Processing Excel Finance. Register for these scheduled courses as your schedule allows - at no extra cost to you.