Like other reviewers advised (and a friend who runs marathons) I ordered a whole size up. I normally wear 7.5 shoe and ordered 8.5. The width and length are great, they are incredibly light and comfortable, they feel great except for they rub my achilles (another reviewer mentioned this also). I've had them for 2 weeks now and they rub a little less, so I wear band-aids to get around blisters. They are so comfortable otherwise I didn't want to return them, and they look great!