I have very narrow feet, with toe-heel 21.9I wear 230 (37 EU) size for tennis shoes, 225 for heels.Everybody said to size up on this one,But do NOT if you have narrow feet. You can see the wrinkles in the image.Sizing up helps you fit in the first time, but once it’s in, there’s leftover spaces especially horizontally, and vertically.But yea it does feel tight around my ankles, i need it tomorrow so I’m not gonna change in. If i could i would go back in time and just stay true to sizeOther than that, awesome show, no discomfort on toes, absolutely breathable and flexible.