I ordered an XL. When they came they appeared SO small that only my 10 year old would fit into them. I was about to return them but then decided to just see if they'd go on. Miraculously, they fit! (It's almost like they're pantyhose in terms of how they can actually stretch to fit your body). I really like them but I don't feel the compression so tightly around my knees. They will work for my purposes and I'm glad I bought them because my knees regularly swell after I do cardio.