ring size conversion chart

Inner Diameter (mm) Inner Circumference (mm) HoH (AU/UK/NZ) US/Canada EU Japan
14.88 46.8 H 4
15.09 47.4 H½ 4.25 46.5 7
15.29 48 I 4.5 47
15.49 48.7 J 4.75 48 8
15.7 49.3 J½ 5 48.5
15.9 50 K 5.25 49 9
16.1 50.6 K½ 5.5 50 10
16.31 51.2 L 5.75 50.5
16.51 51.9 L½ 6 51 11
16.71 52.5 M 6.25 51.5
16.92 53.1 M½ 6.5 52.5 12
17.12 53.8 N 6.75 53 13
17.32 54.4 N½ 7 53.5
17.53 55.1 O 7.25 54.5 14
17.73 55.7 O½ 7.5 55
17.93 56.3 P 7.75 55.5 15
18.14 57 P½ 8 56.5 16
18.34 57.6 Q 8.25 57
18.54 58.3 Q½ 8.5 57.5 17
18.75 58.9 R 8.75 58
18.95 59.5 R½ 9 59 18
19.15 60.2 S 9.25 59.5 19
19.35 60.8 S½ 9.5 60
19.56 61.4 T 9.75 61 20
19.76 62.1 T½ 10 61.5
19.96 62.7 U 10.25 62 21
20.17 63.4 U½ 10.5 63 22
20.37 64 V 10.75 63.5
20.57 64.6 V½ 11 64 23
20.78 65.3 W 11.25 64.5 24
20.93 65.9 W½ 11.5 65.5
21.18 66.6 X 11.75 66 25
21.39 67.2 X½ 12 66.5
21.59 67.8 Y 12.25 67.5
21.79 68.5 Y½ 12.5 68 27
22 69.1 Z 12.75 68.5 28
22.2 69.7 Z½ 13 69
22.4 70.4 Z1 13.25 70 29
22.61 71 13.5 70.5
22.81 71.7 Z2 13.75 71 30
23.01 72.3 Z3 14 72 31
23.22 72.9 14.25 72.5
23.42 73.6 Z4 14.5 73.5 33