I wear a 10.5 shoe so I  ordered a size 11. I think they're a perfect fit. Wearing thin socks they feel comfortably snug due to the thick sheepskin lining but perfect amount of room for toes. The string ties actually work so you can tighten them up if your heel feels like it might slip out. Very comfy overall. I have no idea how long they will last but the quality looks and feels very good. The soles are soft but pretty thick. A word of caution though. These slippers ARE warm so summer wear is out unless your air conditioning is turned up high.