The tutorial shows how to build an amortization schedule in Excel to detail periodic payments on an amortizing loan or mortgage. Loan Amortization Schedule, This spreadsheet creates an amortization schedule for a fixed-rate loan, with optional extra payments.Here is the link to my spreadsheet where you can calculate a loan over x years to be paid back monthly. It will give you the amortized payment amount. This calculator will help you determine the balance of a loan when payments have been different than the negotiated terms. I would like to be able to calculate the remaining amount of loan due after each payment on a loan with irregular payment dates and irregular amounts. No. Due Date, Due Payment, Extra Payment (Recurring), Extra Payment (Irregular), Interest Paid, Principal Paid, Balance. This Excel spreadsheet makes it easy to view the amortization of a home loan with optional extra monthly payments. This spreadsheet makes it easy to track simple, everyday finances.