I ordered an 8&1/2 D. The width is perfect if I wear extremely thin socks, but I'm having trouble with the sewn in tongue. It barely leave enough room for the height of my foot. I suppose if it were looser then the shoe would slip around, but I have to wear a very thin sock. My toes have about 1/2 inch left at the end of the shoe and the widest part of the shoe is hitting at the widest part of my foot, so it appears I have the correct size. I am able to wear my plantar fasciitis inserts, but not my plantar fasciitis bands with this shoes. They are NOT like walking on air, although they have a nice feel. They are super light weight and stylish - very cute! I'll keep them because they will be great for work. I'm a teacher. I would not consider these appropriate for aerobics, hiking, or walking for more than 6 hours. You simply do not have the support in your arch or the side of your shoe. They are very cute!