I'm 5'9" and large-boned (my finger and thumb can't meet around my wrist, which I read somewhere means you are large-boned, and I have size 11 feet). I usually wear a 22 in pants and skirts, but I recently bought a couple of things in size 20. It seems to depend upon the brand and how the clothes are cut -- if they run large I am a size 20. I am wearing a 1X or even a misses XL in most of my tops, although a few of them are 2X (again it seems to depend upon the brand and how they are cut).

I started out wearing a size 28 or 30 (4X). Last winter, I wore size 26 pants until I went below 300 pounds. Somewhere in the 290s I switched into size 24s. I recently tried on a pair of size 26 pants from last winter and they were huge on me -- no way I can wear them anymore.