After a few exchanges, I settled with the Small(7-8). I am a true size 8M. I bought the purple color, which is beautiful. These slippers are very soft and keep my feet from perspiring. However, the material flattened down so quickly, they are now too big. My feet slip forward and my toes end up hanging over the front. I have to consciously walk in them in order to keep them on my feet. Customer service was wonderful when helping with my 2 exchanges (I started with a Sm, thought they were too short, exchanged for a Med, which became way too big after wearing for a few hours, so I went back to a Sm). I'm keeping these because they are the exact slipper I've wanted, but unfortunately, they aren't my favorite or go-to which is what I had hoped they'd be. I will continue searching for the perfect open-toe, shearling slipper that fits more snuggly like a slipper should. These are probably better for a wide foot.