If you are wondering which size I should choose, here are a couple of rules of thumb.
US Men's shoe sizes 6-9 shoe choose MEDIUM size sock
US Men's shoe sizes 10 and up choose LARGE size sock
US Women's shoe size 5.5 to 10 go with a MEDIUM size sock
US Women's shoe size 10.5 and up go with LARGE size sock
This guide is for our Low-Shows NOT our tall socks. Out tall socks fit a much large range of sizes.