A balloon mortgage is usually rather short, with a term of five to seven years, but the payment is based on a term of 30 years. Enter your desired payment and let us calculate your loan amount.Or, enter in the loan amount and we will calculate your monthly payment. This tool figures a loan's monthly and balloon payments, based on the amount borrowed, the loan term and the annual interest rate. Use this calculator to analyze one of your existing loans. Calculate your remaining balance based on the number of monthly payments you have remaining. Balloon Payment Loan Calculator - With this balloon payment calculator you can get the monthly and balloon payment or just the balloon payment itself.