I wear a size 8 and ordered a size 8 and they fit perfectly.  I was worried that the ankle strap would rub or feel tight as i wore them but i didn't even notice it was there, they were super comfortable.

The only negative to them is the sides go down pretty low so when I was walking through a parking lot little rocks got in the shoe and went up to my toes but that can happen with sandals too so I won't take a star away for it.