Ring Size Chart

UK

US

Approximate Inside Diameter (mm)
A 1/2 12.04
A 1/2   12.2
B 1 12.45
B 1/2   12.6
C 1   1/2 12.85
C 1/2   13
D 2 13.26
D 1/2   13.4
E 2   1/2 13.67
E 1/2   13.8
F 3 14.07
F 1/2   14.2
G 3   1/2 14.48
G 1/2   14.6
H 4 14.88
H 1/2   15
I 4   1/2 15.29
I 1/2   15.4
J 4   3/4 15.6
J 1/2   15.8
K 5   1/4 16
K 1/2   16.1
L 5   3/4 16.4
L 1/2   16.6
M 6   1/4 16.8
M 1/2   17
N 6   3/4 17.2
N 1/2   17.4
O 7   1/4 17.6
O 1/2   17.8
P 7   3/4 18
P 1/2   18.2
Q 8   1/4 18.4
Q 1/2   18.6
R 8 3/4 18.8
R 1/2   19
S 9   1/4 19.2
S 1/2   19.4
T 9   3/4 19.6
T 1/2   19.8
U 10   1/4 20
U 1/2   20.2
V 10   3/4 20.4
V 1/2   20.6
W 11   1/4 20.8
W 1/2   21
X 11   3/4 21.2
X 1/2   21.4
Y 12   1/4 21.6
Y 1/2   21.8
Z 12   1/2 22