These are the best socks I've ever owned. The added cushion provides all day comfort. My size falls right on the transition between large and extra-large; I wear a size 13 shoe but a size 12 work boot. I bought the XL figuring it may shrink a little. It did shrink only slightly and fits comfortably snug after washing. I received a pair of Large as a gift and they also fit but they are quite snug. I prefer the XL. If I pull too much on the XL, I can pull the heal of the sock past my heal. I pull it only to where it should be, and it stays comfortably all day without bunching. The L also stays where it should, but the cushion feels stretched a little thinner. Still comfortable though.