Your boy will likely be 6 feet, 4 inches at age 18.
I'd always suspected eventually I'd be looking up at my son but never thought I'd need a crane to do so. Makes sense if you look at my side of the height gene. There's some pretty tall people in my lineage. Not on his father's side so much though. Yeah, his father's half-brother (same mother, different father) is freakishly tall compared to the rest of the family, so maybe one of those freaky genes carried through.
Only time will tell. In the meantime, guess I'd better take him more seriously when he says he wants to be a professional basketball player.