I wear an 8.5 and ordered a US 8.5/Euro 39.5. Listing does not describe width, so I will for you: these are not for wide feet. If you have average-width feet, you'll probably be fine. But the foot bed itself is not wide, and the straps on top of and banding the foot complicate that. These are narrow enough for my feet that the toe strap cannot fit between the base of my toes as it should, so my heels ride right on top of heel ridge at the back of the shoe. The style and color are exactly what I was looking for, and the soft footbed would offer the support I was after.