I WEAR A SIZE 7 AND ORDERED A WHOLE SIZE LARGER BASED ON THE REVIEWS.  WHEN YOU FIRST PUT THIS SHOE ON IT IS VERY TIGHT IN THE MIDDLE OF THE FOOT- HAD TO USE A SHOE HORN BUT ONCE I GOT IT ON IT WAS VERY COMFORTABLE.  HOWEVER, AFTER 2 ZUMBA SESSIONS, IT LOOSENED UP CONSIDERABLY AND I NOW WISH I HAD ORDERED JUST A HALF SIZE LARGER.  THAT BEING SAID, IT'S A GREAT SHOE BUT IT COULD USE MORE ARCH SUPPORT SO I WILL USE AN INSERT WHICH WILL ALSO TIGHTEN IT UP.