Hat sizing cross reference

U.S.

English

Circ. Inches

Circ. CM

6-3/4

6-5/8

21-1/8

54

6-7/8

6-3/4

21-1/2

55

7

6-7/8

21-7/8

56

7-1/8

7

22-1/4

57

7-1/4

7-1/8

22-5/8

58

7-3/8

7-1/4

23

59

7-1/2

7-3/8

23-1/2

60

7-5/8

7-1/2

23-7/8

61

7-3/4

7-5/8

24-1/4

62

7-7/8

7-3/4

24-5/8

63

8

7-7/8

25

64