Set loan terms with larger payments at the end. A Balloon Note is one in which the payments do not fully amortize the value of the Note before its due date.Balloon Loan Payment Calculator. An unsecured promissory note with amortized payments is a promise to pay back a loan when there's no collateral, and it'll be repaid in equal installments. A promissory note is a written commitment to pay someone. This tool figures a loan's monthly and balloon payments, based on the amount borrowed, the loan term and the annual interest rate. Here's the information you'll need to have handy to complete your secured promissory note, installment with balloon final payment.