What size is plus size?

There are number of size in clothing. Size 32, 34,36,38 these are normal size, that means normally people take his/her dress (T-shirt, Tunic, Shirt, Saree, lehenga) in these sizes but over weighted people can not wear in normal size dress then they choose his/her dress in Size 39" or more then size 39". Simply we can say more then Size 38" are called Plus Size.