I ordered these for my father who wears a size 11. He said they were tight against the skin and too uncomfortable to wear. I sent them back and then ordered 13 and they fit perfectly. So I would say the size is bigger. I was put off by the removable/loose insert on the sole, why the heck isn't it attached? But I went back and read the product description and it's intentionally made to be washable. When the insert is in place it is very loose with gaping holes on the sides. There's also a small piece of styrofoam (or cardboard?) that only goes up to the heel. Not sure why? But it's also loose to allow it to slide under the insert. See photos.