These slippers are so soft and warm. Lots of cushion under my feet. I normally wear a size 10, but slippers usually run small. I bought the x-large. Glad I did. Now if I need to I can wear socks with these slippers. Because I sized up and these are too big and don't flop on my feet, I would have to say they might run small. These are very comfortable and will buy another pair as long as the bigger size is available.