I'm a solid 9.5 with my shoe size. I originally ordered 9-9.5 size but sent them back because they were too tight with the toe socks I planned to wear them with. They would have been fine bare foot but I need socks. I purchased these strictly to build up the muscles in my feet. I have plantar fasciitis, and the pain was getting so severe I was having  trouble walking. I started taking Serrapeptase 120000 at the same time I purchased these shoes, and started getting relief instantly. The first time putting them on was frustrating, it took 45 minutes. It wasn't the shoes fault though. I guess I'd never paid attention to my feet. My baby toes were twisted and smashed tight against the other toe. Once you get them on it really spreads all of your toes apart, and as I walk it feels more stable. My feet take up 1.5x the space than when in a regular shoe. Every time I put them on it got easier, after a month it would only take a few minutes. I don't wear these daily either. From the first time I started wearing them I could feel the muscles in the front of my leg being developed and my knee pain has also disappeared. I'm sure it's a combo of Serrapeptase and these shoes because I get regular blood work, and the inflammation in my blood went from high to normal levels.