I ordered the original Ascot; Color Blue; Size 12 It was too small, so I took it to a store in San Marcos TX. They had a size 13 and they swapped it out without a word. While my wife and I were there I saw a Slipper. I tried it on and it just so happened that they had the color I would have been looking for...So, I bought another pair while I was there.
I usually wear a size 10 or occasionally a 10 1/2 but I couldn't come close to getting my foot into a 10 with this slipper. I exchanged for an 11 and can get them on, but they are still snug. I'm assuming that they will become more comfortable as the fleece lining packs down some.
Go with a size up for easy slide on and comfort.. and make sure you go with the wide foot option if you have some weight on you or your foot seems to widen out shoes.. not noticeable and much more comfortable on foot.. great option they offer..!