I ordered medium and I wear a size 7 1/2 shoe about 95 percent of the time. Occasionally, I need a size 8. The slippers are way too small for my feet, though, not just slightly snug. I could not possibly wear them, thinking they might stretch a bit. They are very cute, although they do not appear to be made to last, especially the rather thick cushioning in the sole which has very little density and compresses easily. Still, for the $14.99 advertised sale price, I would have been satisfied if they had fit.  However, I see now that I was charged $30 for these slippers, despite the advertised sale price. It's odd I didn't notice that before hitting the purchase button and I'll remember to check more carefully in the future. In my estimation, the slippers are not worth $30. In any event, I was easily able to print out a return label, they are already on their way back to Amazon and the product page states they qualify for free return, making this transaction not very painful at all.