I wear a size 12 and followed the reviews indicating the Medium would be more appropriate. They are a little snug which is emphasized since they are heels which obviously press the toes to the front. The box says they fit US size 10-11, which seems about right. I think they will still work for a disco party I got them for, but guessing my feet may be a little sore the next day. The next size larger may be a bit too big based on the reviews, but I wouldn't know. They look amazing though and can't wait to rock them!
Rating: [4 of 5 Stars!]