Size Chart

Japan

Circumference

(Diameter)

UK USA
7

46.8mm

(14.9mm)

H 4
8

48mm

(15.3mm)

I 4 1/2
9

49.3mm

(15.7mm)

J 1/2 5
10

50.6mm

(16.1mm)

K 1/2 5 1/2
11

51.9mm

(16.5mm)

L 1/2 6
12

52.5mm

(16.7mm)

M -
13

53.1mm

(16.9mm)

M 1/2 6 1/2
14

54.4mm

(17.3mm)

N 1/2 7
15

55.7mm

(17.7mm)

O 1/2 7 1/2
16

57mm

(18.1mm)

P 1/2 8
17

58.3mm

(18.5mm)

Q 1/2 8 1/2
18

59.5mm

(19mm)

R 1/2 9
19

60.8mm

(19.4mm)

S 1/2 9 1/2
20

62.1mm

(19.8mm)

T 1/2 10
21

62.7mm

(20mm)

U -