My husband wears a 12 shoe so I got him the 12-13 and they fit.  I did NOT mention the Acorn embroidered emblem in the heel area--that really is a bad place to put one--for fear he'd start noticing it.  He wears socks with them so maybe he really doesn't feel it.  They seem to be made well.  I haven't washed them yet, but that's the main reason I bought these was because they were machine washable.

Downgraded my review after wearing for a few days.  I don't know if I can explain this well enough, but the way these fit my husband, the slipper soles roll to the outside.  He can't keep them from rolling and he feels like he's going to hurt his ankle.  It's like having a sock that turns just from wearing it.