The indepth Watch Me Build is a 25 minute behemoth, showing you how to build a more complex, dynamic amortization table in Excel. Use the following formulas to show the total payment, interest portion of the payment, and principal portion of the payment.Microsoft Excel Mortgage Caculator XLS Worksheet. With our inputs converted into the right units, we're now ready to build our mortgage amortization table in Excel. Almost any data field on this form may be calculated. Mortgage interest rate. Use the farm or land loan calculator to determine monthly, quarterly, semiannual or annual loan payments. Get ag-friendly, farm loan rates and terms. Enter the price of a home and down payment amount to calculate your estimated mortgage payment with an itemized breakdown and schedule. There are three fields to fill in: home price, down payment and mortgage interest rate.