US Men	US Women	Euro	UK	Calf Circumference
Small	3 - 5.5	4 - 6.5	34 - 37	2 - 4.5	11" - 14.5"
Medium	6 - 8.5	7 - 9.5	38 - 41	5 - 7.5	12.5" - 16.5"
Large	9 - 11.5	10 - 12.5	42 - 45	8 - 10.5	14.5" - 18"
X-Large	12 - 14.5	n/a	46 - 49	11 - 13.5	16" - 23"