I have a very narrow foot and it's very thin.  I think for most people the shoe size is correct.  Size 5's typically are a bit big for me, but these fit pretty close.  I love that you can adjust the strap which has helped tremendously.  The arch support is the best I've ever had in any shoe.  I wear them to work and I'm on my feet a lot during the day.  I have several herniated discs in my neck from a drunk driver hitting me several years ago.  These have been the only shoes I've managed to wear all day long and not have a limp.  I highly recommend them.