I have EXTREMELY flat feet, and because I have ignored that fact for the first 25 years of my life - I now have some painful foot issues.  When I put these shoes on the first time, my entire body went, "Ahhhh.."  My feet feel better, by knees feel better, my back feels better.. you get the point.  I normally wear something between a 10 and an 11 in shoes, depending on the brand/style, and the 10 in these fits me very well.  I would also like to note that I inadvertently ordered a wide in these, but it turned out to be a happy mistake, as I no longer have a problem with my toes falling asleep after and hour on my elliptical.  Great shoes!  I will buy them again!