Round about 80-90 cm give or take : D
there is no exact answer, but in general, dreads shrink for the 1st 10 months or so, then begin to grow. once dreads begin to grow they never stop.
three years
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!
It would actually probably take among three years to grow it around or almost to your waist.