RING SIZE GUIDE
AU/UK DIAMETER (mm)
I 15.2 mm
I 1/2 15.4 mm
J 15.6 mm
J 1/2 15.8 mm
K 16.0 mm
K 1/2 16.1 mm
L 16.4 mm
L 1/2 16.6 mm
M 16.8 mm
M 1/2 17.0 mm
N 17.2 mm
N 1/2 17.4 mm
O 17.6 mm
O 1/2 17.8 mm
P 18.0 mm
P 1/2 18.2 mm
Q 18.4 mm
Q 1/2 18.6 mm
R 18.8 mm
R 1/2 19.0 mm
S 19.2 mm
S 1/2 19.4 mm
T 19.5 mm
T 1/2 19.8 mm
U 19.9 mm
EUROPEAN DIAMETER (mm)
48 15.3 mm
49 15.6 mm
50 15.9 mm
51 16.2 mm
52 16.6 mm
53 16.9 mm
54 17.2 mm
55 17.5 mm
56 17.8 mm
57 18.1 mm
58 18.5 mm
59 18.8 mm
60 19.1 mm
61 19.4 mm
61.5 19.84 mm
US DIAMETER (mm)
5 15.6 mm
5 ½ 16.0 mm
6 16.4 mm
6 ½ 16.8 mm
7 17.2 mm
7 ½ 17.6 mm
8 18.0 mm
8 ½ 18.4 mm
9 19.2 mm
10 19.84 mm
For further information on sizing, check out the international ring size conversion chart.