I ordered a pair of mediums (8-9) I wear a 9 normally in any shoe. These were too small. My toes were hittening the end of the shoe just when standing.
I ordered the size large, and got them 3 days later. I still have to return the other pair.
The new pair feel big, so I'm going to wear tem to work, and see how they "wear" If they work out well, I will take then to my DW trip in June.