RING SIZE

International Conversion Chart
Diameter (mm)
Perimeter (mm)
ISO
UK, Australia, Ireland, New Zealand, South Africa
USA, Canada, Mexico
Germany
Switzerland, Netherlands, Spain, Italy
Singapore, Japan, Taiwan, Korea
China, Hong Kong, India
11.53
36.2
36
-
00
11.95
37.52
38
A
1/2
12.18
38.25
38
A 1/2
3/4
12.37
38.84
39
B
01
1
12.6
39.56
40
B 1/2
1+1/4
12.78
40.13
40
C
1+1/2
13
40.82
41
C 1/2
1+3/4
13.21
41.48
42
D
02
13+1/2
1+1/2
2
13.41
42.11
42
D 1/2
2+1/4
13.61
42.74
43
E
2+1/2
13+3/4
2+3/4
3
13.83
43.33
43
E1/2
2+3/4
14.01
43.99
44
F½
3
14
4
4
6
14.33
45
45
G
5
14.4
45.22
45
5+1/4
7
14.5
45.53
46
G½
3½
14+1/2
14.65
46
46
H
6+1/2
6
8
14.97
47.01
47
H½
4
15
7
9
15.1
47.41
47
I
7+3/4
15.29
48.01
48
I½
4½
15+1/4
8
15.5
48.67
49
J
15+1/2
9
10
15.61
49.02
49
J½
5
15+3/4
9
15.8
49.61
50
11
15.92
49.99
50
K
10
16.1
50.55
51
K½
5½
10
16.24
50.99
51
L
12
16.4
51.5
52
16
11+3/4
16.56
52
52
L½
6
16+1/2
12+3/4
11
13
16.7
52.44
52
M
12
16.88
53
53
M½
6½
17
14
13
14
17.1
53.69
54
N
17.2
54.01
54
N½
7
17+1/4
15+1/4
14
15
17.52
55.01
55
O
16
17.7
55.58
56
O½
7½
17+3/4
16+1/2
15
17.83
55.99
56
P
17
18.15
56.99
57
P½
8
18
17+3/4
16
18.2
57.15
57
18
18.3
57.46
57
Q
18+1/2
18.47
58
58
Q½
8½
19
17
19
18.79
59
59
R
19
59.66
60
R½
9
19
18
20
19.11
60.01
60
S
20+1/4
19.43
61.01
61
S½
9½
19+1/2
19
21
19.6
61.54
62
T
21+1/2
22
19.75
62.02
62
T½
10
20
20
20
62.8
63
U
22+3/4
21
23
20.06
62.99
63
U½
10½
20+1/4
22
20.38
63.99
64
V
23+3/4
24
20.6
64.68
65
V½
11
20+3/4
23
20.7
65
65
W
25
25
21.02
66
66
W½
11½
21
24
26
21.2
66.57
67
X
26+1/4
21.34
67.01
67
X½
12
21+1/4
27+1/2
25
27
21.6
67.82
68
Y
21.66
68.01
68
Z
12½
21+3/4
28+3/4
26
21.97
68.99
69
Z½
22.29
69.99
70
13
22
27
30
22.4
70.34
70
Z+1
22.61
71
71
Z+2
13½