I usually wear a size11M but since it wasn't available, I bought the size 10W. I don't have a wide foot but figured Id rather have it a little loose. I was so disappointed that the sandals fit very tight across the top of my feet and caused red spots on my left great toe joint within 5 minutes of wearing them. The rest of the sandals look nice so I purchased shoe stretchers to see if I can widen them. If you have a true wide foot, do not purchase these.