I purchased this particular size for my son because he had other packs of Hanes size M previously, that we were looking to replace. I had tried the size L for him but they were too big, as they fit me. [Woman's size 9.] These newer versions seem to run small. He can still fit into his older size Ms but the new ones I purchased were too small from the beginning. I actually ended up giving them to my daughter, who was wearing a child's size 11 shoe at the time. Otherwise they are great socks, I just wish he would have actually been able to fit into them.