I normally wear a 6.5 to 7 depending on the shoe.  I figured I'd go ahead and get the 7 just in case.  They are a teeny bit too big, but the strap keeps it in place so I don't really notice.  They are the most comfortable things I've ever worn though.  I could imagine walking all day in them.  The straps are just snug enough that I don't worry about them slipping off, without being so tight I feel my foot is being strangled.  I would definitely recommend them to friends.  I might have to buy a pair for my mom as well.