I usually wear size 11 to 11.5, D to EEE depending on the shoe brand. Based on the seller/manufacturer's recommendation to buy 1/2 size larger than usual, combined with numerous reviews that the slippers are about 2 sizes too small, I decided to purchase 12 EEE. The slippers appeared to be well made: the details were well tailored and fitted well, and the stitching was clean. However, I had at least 3/4 inch of free space behind my ankle. I'll return them and try 11 EEE next time. Hope they don't get too small. many other reviewers and you just have to guess whether to order your normal size, a slightly larger size or a much larger size. The first pair I bought was $33.75 and a week later a new pair is currently $47.25 (I checked different sizes both times and confirmed the price was the same both times regardless of size) . Get slippers that don't fit you, no matter how hard you try to predict what size you need, the seller should even allow an exchange or at least respect the original price if you have to return the slippers and try on a different size. I wish this brand was easier to find in a physical store where I could try them on before buying and wait a week or two to get them.