goldringsplus.com ring sizing conversion guide
United States
sizes
Great Britain
sizes
Japanese
sizes
Inner
Diameter in
millimeters
Inner
Circumference
in millimeters
3 G - 14.5 mm 45.5 mm
3 G 6 14.7 mm 46.1 mm
4 H 7 14.9 mm 46.6 mm
4 H - 15.1 mm 47.3 mm
4 I 8 15.3 mm 48 mm
4 I - 15.5 mm 48.6 mm
4 ^ J - 15.5 mm 48.8 mm
5 J 9 15.7 mm 49.3 mm
5 K - 15.9 mm 49.9 mm
5 K 10 16.1 mm 50.6 mm
5 L - 16.3 mm 51.2 mm
6 L 11 16.5 mm 51.8 mm
6 M 12 16.7 mm 52.5 mm
6 M - 16.9 mm 53.1 mm
6 N 13 17.1 mm 53.8 mm
7 N 14 17.3 mm 54.3 mm
7 O - 17.5 mm 55 mm
7 O 15 17.7 mm 55.7 mm
7 P - 17.9 mm 56.3 mm
United States
sizes
Great Britain
sizes
Japanese
sizes
Inner
Diameter in
millimeters
Inner
Circumference
in millimeters
8 P 16 18.1 mm 56.9 mm
8 Q - 18.3 mm 57.5 mm
8 Q 17 18.5 mm 58.1 mm
8 R - 18.7 mm 58.9 mm
9 R 18 18.9 mm 59.5 mm
9 S - 19.1 mm 60.1 mm
9 S 19 19.4 mm 60.8 mm
9 T - 19.6 mm 61.4 mm
10 T 20 19.8 mm 62.2 mm
10 U 21 20 mm 62.7 mm
10 U 22 20.2 mm 63.5 mm
10 V - 20.4 mm 64.1 mm
11 V 23 20.6 mm 64.7 mm
11 W - 20.8 mm 65.2 mm
11 W 24 21 mm 65.9 mm
11 X - 21.2 mm 66.5 mm
12 X 25 21.4 mm 67.2 mm
12 Y - 21.6 mm 67.9 mm
12 Y 26 21.8 mm 68.5 mm
12 Z - 22 mm 69.1 mm
13 Z + 1 - 22.4 mm 70.3 mm
13 Z + 2 - 22.8 mm 71.6 mm
14 Z + 3 - 23.2 mm 72.9 mm