I don't really think there is a terminal length tbh because when I was younger my hair used to grow past my butt but I hacked it all off for the first time when I was 11. It had maintained around shoulder length without me doing anything at all ever since. But Sept. 2012 when I wanted to grow it out and go natural I began to do research on proper hair care and within a matter of months it began growing better and healthier and now it's 2-3 inches from waist length straightened.. so I think it really depends on your regimen and how much you are willing to work for it and care for it