I have what I call a "Fred Flintstone" foot - very wide. I usually take (in sneakers) a Mens 8.5 EEEE. These slippers fit soooooo well, plenty of room for my wide feet and soft foam inside. I'm in heaven. Thanks you for making a great product. Oh, of you were hesitant to make a purchase -- DO IT, you will be very happy.ADDENDUM: I ordered a second pair because these are honestly the most comfortable slipper I have ever owned.