No two stones alike
-->
International Ring Size converter
N.B.: The measurements in this chart contain conversions and are approximate.
Inside Circumference Inside Diameter Sizes
(in) (mm) (in) (mm) USA & Canada UK, Eire, AU
1.94
49.3
0.618
15.7
5
J 1/2
1.97
50
0.626
15.9
5 1/4
K
1.99
50.6
0.634
16.1
5 1/2
K 1/2
2.02
51.2
0.642
16.31
5 3/4
L
2.04 51.9
0.65
16.51
6
L 1/2
2.07
52.5
0.658
16.71
6 1/4
M
2.09 53.1
0.666
16.92
6 1/2
M 1/2
2.12
53.8
0.674
17.12
6 3/4
N
2.14 54.4
0.682
17.32
7
N 1/2
2.17
55.1
0.69
17.53
7 1/4
O
2. 1955.7
0.698
17.73
7 1/2
O 1/2
2.22
56.3
0.706
17.93
7 3/4
P
2.24
57
0.714 18.14
8
P 1/2
2.27
57.6
0.722
18.34
8 1/4
Q
2.29
58.3
0.73 18.54
8 1/2
Q 1/2
2.32
58.9
0.738
18.75
8 3/4
R
2.34
59.5
0.746 18.95
9
R 1/2
2.37
60.2
0.754
19.15
9 1/4
S
2.39
60.8
0.762 19.35
9 1/2
S 1/2
2.42
61.4
0.77
19.56
9 3/4
T
2.44
62.1
0.778 19.76
10
T 1/2
2.47
62.7
0.786
19.96
10 1/4
U
2.49
63.4
0.794 20.17
10 1/2
U 1/2
2.52
64
0.802
20.37
10 3/4
V
2.54
64.6
0.81 20.57
11
V 1/2
2.57
65.3
0.818
20.78
11 1/4
W
2.59
65.9
0.826 20.98
11 1/2
W 1/2
2.62
66.6
0.834
21.18
11 3/4
X
2.65
67.2
0.842 21.39
12
X 1/2
2.67
67.8
0.85
21.59
12 1/4
Y
2.7
68.5
0.858 21.79
12 1/2
Z
2.72
69.1
0.866
22
12 3/4
Z 1/2
2.75
69.7
0.874 22.2
13
2.77
70.4
0.882
22.4
13 1/4
Z1
2.8
71
0.89 22.61
13 1/2
2.82
71.7
0.898
22.81
13 3/4
Z2
2.85
72.3
0.906
23.01
14
Z3
2.87
72.9
0.914
23.22
14 1/4
2.9
73.6
0.922
23.42
14 1/2
Z4
2.92
74.2
0.93
23.62
14 3/4
2.95
74.8
0.938
23.83
15
