These socks run very small.
"My feet are very wide in the toe area, and while I have small ankles, my calves are big. I have a hard time finding socks wide enough for both my feet and calves. I was so excited to try these socks when they first were available, and ordered my normal size medium. Unfortunately, they were too tight and too short. Fast forward a year and I decided to order a few pairs in a size large. Voila, they fit! Then I compared the Wide Open large to a few pairs of Darn Tough and Smart Wool mediums, and discovered they were the same size! So buyer beware, these socks run a whole size smaller than other wool socks."