Returns the payment per month reach a certain amount in the future, assuming constant payments and interest rate. Loan Payment Calculation.You can use the software program Excel to calculate your loan repayments. This article is a step-by-step guide to setting up loan calculations. The APR and the sum of your selected cash incentives are auto-filled in the calculator. Amortization Schedule Google Sheets Template. 2007 Form AK Mat Su Title Agency Owner Finance Terms Fill Online.