Fitting by Shoe Size: X-Small (M: 6-7) (W:5-6), Small (M:7.5-9) (W:6.5-8), Medium (M:9.5-11) (W:8.5-12), Large (M:11.5-13) (W:12.5-14), X-Large (M:13-15) For wider feet, please select one size up.