Ā 

INTERNATIONAL RING SIZE CHART
Inside Diameter (mm) Inside Circumference (mm) US UK/AU
14.1 44.3 3 F
14.3 44.9 3.25 F 1/2
14.5 45.6 3.5 G
14.7 46.2 4 G 1/2
14.9 46.8 4 H
15.1 47.4 4.25 H 1/2
15.3 48.1 4.5 I
15.5 48.7 4.75 I 1/2
15.7 49.3 5 J
15.9 50 5.25 J 1/2
16.1 50.6 5.5 K
16.3 51.2 5.75 K 1/2
16.5 51.8 6 L
16.7 52.5 6.25 L 1/2
16.9 53.1 6.5 M
17.1 53.7 6.75 M 1/2
17.3 54.3 7 N
17.5 55 7.25 N 1/2
17.7 55.6 7.5 O
17.9 56.2 7.75 O 1/2
18.1 56.9 8 P
18.3 57.5 8.25 P 1/2
18.5 58.1 8.5 Q
18.8 59.1 8.75 Q 1/2
19 59.7 9 R
19.2 60.3 9.25 R 1/2
19.4 60.9 9.5 S
19.6 61.6 9.75 S 1/2
19.8 62.2 10 T
20 62.8 10.25 T 1/2
20.2 63.5 10.5 U
20.4 64.1 10.75 U 1/2
20.6 64.7 11 V
20.8 65.3 11.25 V 1/2
21 66 11.5 W
21.2 66.6 11.75 W 1/2
21.4 67.2 12 X
21.6 67.9 12.25 X 1/2
21.8 68.5 12.5 Y
22 69.1 12.75 Z
22.2 69.7 13 Z 1/2