I first ordered my usual size 11 but found it very tight. For some reason I didn't want to believe other reviewers who said they ran small. YOU'RE RIGHT! Then I ordered 11.5 and 12 and ended up returning 11.5 and kept 12 so the lesson here is to order a full size for a good fit. In addition, the slippers are of excellent quality, they are easy to put on and take off, and the leather sole is ideal for shoes that do not leave scratches. I recently spent a lot of time visiting a wonderful lady who designed hardwood floors and they seem to scratch easily with any rubber sole. These soft leather soles are the answer. Excellent work!