Inches:
20-3/4
21-1/8
21-1/2
21-7/8
22-1/4
22-5/8
23
23-1/2
23-7/8
24-1/4
24-5/8
25
25-1/2
Hat Size:
6-5/8
6-3/4
6-7/8
7
7-1/8
7-1/4
7-3/8
7-1/2
7-5/8
7-3/4
7-7/8
8
8-1/8
Metric Size:
53
54
55
56
57
58
59
60
61
62
63
64
65