Inside Circumference

Sizes

MM

Inches

British & Australian

US & Canada

46.68

1.84

H 1/2

4

47.97

1.89

I 1/2

4 1/2

49.32

1.94

J 1/2

5

50.58

1.99

L

5 1/2

51.87

2.04

M

6

53.16

2.09

N

6 1/2

54.51

2.15

O

7

55.76

2.20

P

7 1/2

57.15

2.25

Q

8

58.21

2.29

Q 3/4

8 1/2

59.34

2.35

R 3/4

9

60.98

2.40

S 3/4

9 1/2

62.33

2.45

T 1/2

10

63.46

2.50

U 1/2

10 1/2

64.97

2.56

V 1/2

11

66.22

2.61

W 3/4

11 1/2

67.51

2.66

Y

12

68.77

2.71

Z

12 1/2

70.15

2.76

Z+1

13

71.00

2.80

Z+1.5

13 1/2