I think you need to look at the feet. I am 6'2" size 11 shoe. My wife is 5'9" size 9.5. My oldest son is 17 and 6'5" size 13 shoe. I'm pretty sure he is done growing. My 15 year old son is 6'4" and wears a 14.5 to 15, depending on the shoe. I don't think he is anywhere near done. My wife and I both have close relatives bigger than us. Both of my son's were 10lb+ at birth and have grown very steadily their whole lives. My wife's brother grew from 5'10" to 6'3" in college. I think it varies widely in every individual.