How much do you have to weigh and how tall do you have to be to ride in the front seat in Tennessee?

Well for starters babies cannot ride on the front seat also toddlers cant either both ground have to be in the back seat properly strapped to the seat.

Around your early teens you may be allowed to ride front seat.

i do not think you should base that on weight or height since they will be people who are real tall and are under age or are over weight and are under age as well.