How vanity sizing works online? Ok, the title is stupid but I really don't know how to put it better. I read a lot about vanity sizing, and it's something that happened to me too, since I usually wear an M everywhere but I bought recently a sweater that is a XS. The thing that struck me is the online sizing charts of various sites, because in ALL I'm a 6-8 US, even in shops that are famous for vanity sizing. They use false measurements? If they say that a M need a 30" waist than in reality a M shirt is bigger? I'm confused, really, maybe because I live in a country where we have the opposite of vanity sizing.