International ring size comparison chart

WILLS JEWELLERY uses Hong Kong's size measurement system. You can find the size that suits you according to the following size comparison table. 

Inner ring diameter
(mm)
Hong Kong Circle American circle british circle Japan Swiss Circle
14.1 6 3 F 4 4
14.3 7 3.25 F 1/2 5 5.25
14.7 8 3.75 G 6 6.5
14.9 9 4 H 7 7
15.3 10 4.5 I 8 8.5
15.7 11 5 J 1/2 9 9.5
16.1 12 5.5 K 1/2 10 10.5
16.5 13 6 L 1/2 11 12.75
16.7 14 6.25 M 12 13.5
17.1 15 6.75 N 13.5 14.5
17.3 16 7 N 1/2 14 15.25
17.7 17 7.5 The 1/2 15 16.5
18.2 18 8 P 1/2 16.25 18.25
18.5 19 8.5 Q 1/2 17 18.75
18.8 20 9.75 R 17.5 19
19.1 21 9.25 S 18 20
19.4 22 9.5 S 1/2 19 20.75
19.8 23 10 T 1/2 20 21.75
20.2 24 10.5 In 1/2 22 22.75
20.6 25 11 In 1/2 23 24.75
21.0 26 11.5 In 1/2 24 26.25
21.2 27 12 X 24.5 26.75
21.6 28 12.25 AND 25.5 28
22.0 29 12.5 With 1/2 26.5 29