a couple of things to point out, with your math I see the problem right away, its not a lump sum figure when you reinvest its not one big loan just the base loan and reinvest loans after that, when you are compounding each reinvest starts a new loan. and the length of the loan depends on the amount of the reinvest which is dictated by the amount of months. which can be 4 months, 6 months 8 months or 10 months.so when your base loan matures u will have other loans coming due depending on the amount of the reinvest. I hope I did not confuse you.