I'm a medium width and take a 9.5 this is my first time buying this brand, I know now to order a 9 in this particular brand I have purchased the FitFlop Yoko Thong Sandal in a 9 with some helpful hints from other reviews I ordered a size 9 and I can walk in them all day my back doesn't hurt, my knee feels a lot better and it is really true you have energy throughout your legs and feet. I just wanted another style other than a Thong and my next style to try will be Clogs, and Athletic type shoe and we'll see the sizing on those but all and all I'm very pleased with the foot support you get with these shoes. I will be ordering them in other styles for sure.