Ring Size Conversion Chart

Inside Circumference Inside Diameter
US & Canada
Europe
UK & Australia
Japan & Singapore
IN MM MM
1.74 44.3 14.1 3 44 F 1/2 4
1.77 44.9 14.3 3.25 45 G 5
1.79 45.6 14.5 3.5 G 1/2
1.82 46.2 14.7 3.75 46 H 6
1.84 46.8 14.9 4 47 H 1/2 7
1.87 47.4 15.1 4.25 I
1.89 48.1 15.3 4.5 48 I 1/2 8
1.92 48.7 15.5 4.75 J
1.94 49.3 15.7 5 49 J 1/2 9
1.97 50.0 15.9 5.25 50 K
1.99 50.6 16.1 5.5 K 1/2 10
2.02 51.2 16.3 5.75 51 L
2.04 51.8 16.5 6 52 L 1/2 11
2.07 52.5 16.7 6.25 M 12
2.09 53.1 16.9 6.5 53 M 1/2 13
2.12 53.7 17.1 6.75 N
2.14 54.3 17.3 7 54 N 1/2 14
2.16 55.0 17.5 7.25 55 O
2.19 55.6 17.7 7.5 O 1/2 15
2.21 56.2 17.9 7.75 56 P
2.24 56.9 18.1 8 57 P 1/2 16
2.26 57.5 18.3 8.25 Q
2.29 58.1 18.5 8.5 58 Q 1/2 17
2.33 59.1 18.8 8.75 59 R
2.35 59.7 19 9 R 1/2 18
2.37 60.3 19.2 9.25 60 S
2.40 60.9 19.4 9.5 61 S 1/2 19
2.42 61.6 19.6 9.75 T
2.45 62.2 19.8 10 62 T 1/2 20
2.47 62.8 20 10.25 U 21
2.50 63.5 20.2 10.5 63 U 1/2 22
2.52 64.1 20.4 10.75 64 V
2.55 64.7 20.6 11 V 1/2 23
2.57 65.3 20.8 11.25 65 W
2.60 66.0 21 11.5 66 W 1/2 24
2.62 66.6 21.2 11.75 X
2.65 67.2 21.4 12 67 X 1/2 25
2.67 67.9 21.6 12.25 Y
2.70 68.5 21.8 12.5 68 Z 26
2.72 69.1 22 12.75 69 Z 1/2
2.75 69.7 22.2 13 70 27
2.77 70.4 22.4 13.25 Z+1
2.80 71.0 22.6 13.5 Z+2