My company has a loan taken out on 8/25/17 for $122,100.00 with a purchase amount of $170,940 (this is the total payment amount). The payments of $1,187.09 start on 8/28/17 and are Monday through Friday, except for holidays. The number of payments is 144 (with the last payment being $1,186.13. I am trying to calculate the amortization schedule so I can book the principle payments versus interest payments. For audit purposes, I need the amount of interest expense paid in 2017. I believe the interest rate is close to 90%, but am not sure how to calculate. Please help! Thank you.