[sizes are approximate]
Adult S = Kid's shoe size 3 to 51⁄2 or women's 4 to 61⁄2
Adult M = Men's 6 to 81⁄2 or women's shoe 7 to 91⁄2
Adult L = Men's shoe 9 to 111⁄2 or women's 10 to 121⁄2
Adult XL = Men's shoe size 12 to 141⁄2
Kids XS = Infant shoe size 6 to youth shoe size 81⁄2
Kids S = Youth shoe size 9 to size 111⁄2
Kids M = Youth shoe size 12 to 21⁄2
Kids L = Big kid's shoe size 3 to 6 or Women's 4 to 7
Best is to turn the socks inside out and wash on gentle cycle in warm or cold water. Don't use bleach or fabric softner. Tumble dry at low setting.