I usually wear a 10 w in tennis shoes, but for flats/loafers/heels I usually wear 9 1/2 W.  These shoes are a little tight once you first start wearing them, but I have only had them for a a little over a day and they are already loosening up a bit.  They are very comfortable and look great with most everything.  Superbly comfortable and no break-in period.  You won't regret buying them.