Also, the sizings change between countries. I wear a size 8-10 here, but that is like, 4-6 or something in America. Also, a size 8 might fit me in one brand, but I might need a size 10 in a different brand, or a size 6 in another, which makes it even more annoying.
So, uh, the numbers for sizings are supposed to be for certain measurements, but the fact that they are nuts makes them not as useful as they could be.