Inches	Size		Metric
21 1/4	6 3/4	XX-Small	54
21 5/8	6 7/8		55
22	7	X-Small	56
22 3/8	7 1/8	Small	57
22 3/4	7 1/4	Medium	58
23 1/8	7 3/8		59
23 1/2	7 1/2	Large	60
23 7/8	7 5/8		61
24 1/4	7 3/4	X-Large	62
25 1/8	8	XX-Large	64
25 1/2	8		65
25 7/8	8 1/4		66
26 1/4	8 1/4		67
26 3/8	8 1/2		68