Ring Size Chart

Inner 
Diameter

Country Standard

(mm) HK US UK Swiss Japan
14.9 9 4 H 7 7
15.3 10 4.5 I 8.5 8
15.7 11 5 J 1/2 9.5 9
16.1 12 5.5 K 1/2 10.5 10
16.5 13 6 L 1/2 12.75 11
16.7 14 6.25 M 13.5 12
17.1 15 6.75 N 14.5 13.5
17.3 16 7 N 1/2 15.25 14
17.7 17 7.5 O 1/2 16.5 15
18.2 18 8 P 1/2 18.25 16.25
18.5 19 8.5 Q 1/2 18.75 17