5 weeks
It would actually probably take among three years to grow it around or almost to your waist.
The average is 15 to 18 inches - however, there are exceptions.
A couple or more years. I should know! I had hair that was nearly up to my bottom but I got it cut the other day. Shame!
3 months
Well Megalodon adults can grow over 75 ft. The babies are about 25 ft.