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. Does anyone know how to calculate the principal and interest payments after a one time extra principal payment on a mortgage in excel? This spreadsheet creates an amortization schedule for a fixed-rate loan, with optional extra payments. To use our amortization calculator, type in a dollar figure under "Loan amount. Expense tracker apps help you collect and classify your purchases so that you recognize spending patterns and spot where to trim your costs.