These socks run small, I wear a size 11 in Red Wings and other true-to-size brands that correspond with the actual dimensions of the foot and a size 13 in brands that use vanity sizing such as Nike. Darn Tough's L is too tight for me so I will have to send them back and try the XL size. It's a shame that these follow the standard of vanity sizing that is common in US department store brands because it makes it difficult to find an accurate size, especially when buying online.

EDIT: Though the sizing is annoying, these are great summer boot socks.