Ring Size Conversion.
Diameter |
Circumference |
US/Canada |
British |
Japanese |
Swiss |
(mm) |
(mm) |
Standard |
Irish |
|
|
|
|
|
Australian |
|
|
|
|
|
|
|
|
11.6 |
36.5 |
0 |
|
|
|
11.8 |
37.2 |
1/4 |
|
|
|
12.0 |
37.8 |
1/2 |
A |
|
|
12.2 |
38.4 |
3/4 |
A 1/2 |
|
|
12.4 |
39.1 |
1 |
B |
1 |
|
12.6 |
39.7 |
1 1/4 |
B 1/2 |
|
|
12.9 |
40.4 |
1 1/2 |
C |
|
|
13.1 |
41.0 |
1 3/4 |
C 1/2 |
|
|
13.3 |
41.6 |
2 |
D |
2 |
1.50 |
13.5 |
42.3 |
2 1/4 |
D 1/2 |
|
|
13.7 |
42.9 |
2 1/2 |
E |
3 |
2.75 |
13.9 |
43.5 |
2 3/4 |
E 1/2 |
|
|
14.1 |
44.2 |
3 |
F |
4 |
4.00 |
14.3 |
44.8 |
3 1/4 |
F 1/2 |
5 |
5.25 |
14.5 |
45.5 |
3 1/2 |
G |
|
|
14.7 |
46.1 |
3 3/4 |
G 1/2 |
6 |
6.50 |
14.9 |
46.7 |
4 |
H |
7 |
|
15.1 |
47.4 |
4 1/4 |
H 1/2 |
|
7.75 |
15.3 |
48.0 |
4 1/2 |
I |
8 |
|
15.5 |
48.7 |
4 3/4 |
J |
|
9.00 |
15.7 |
49.3 |
5 |
J 1/2 |
9 |
|
15.9 |
49.9 |
5 1/4 |
K |
|
10.00 |
16.1 |
50.6 |
5 1/2 |
K 1/2 |
10 |
|
16.3 |
51.2 |
5 3/4 |
L |
|
11.75 |
16.5 |
51.8 |
6 |
L 1/2 |
11 |
12.75 |
16.7 |
52.5 |
6 1/4 |
M |
12 |
|
16.9 |
53.1 |
6 1/2 |
M 1/2 |
13 |
14.00 |
17.1 |
53.8 |
6 3/4 |
N |
|
|
17.3 |
54.4 |
7 |
N 1/2 |
14 |
15.25 |
17.5 |
55.0 |
7 1/4 |
O |
|
|
17.7 |
55.7 |
7 1/2 |
O 1/2 |
15 |
16.50 |
17.9 |
56.3 |
7 3/4 |
P |
|
|
18.1 |
56.9 |
8 |
P 1/2 |
16 |
17.75 |
18.3 |
57.6 |
8 1/4 |
Q |
|
|
18.5 |
58.2 |
8 1/2 |
Q 1/2 |
17 |
|
18.7 |
58.9 |
8 3/4 |
R |
|
19 |
18.9 |
59.5 |
9 |
R 1/2 |
18 |
|
19.2 |
60.1 |
9 1/4 |
S |
|
20.25 |
19.4 |
60.8 |
9 1/2 |
S 1/2 |
19 |
|
19.6 |
61.4 |
9 3/4 |
T |
|
21.5 |
19.8 |
62.1 |
10 |
T 1/2 |
20 |
|
20.0 |
62.7 |
10 1/4 |
U |
21 |
|
20.2 |
63.3 |
10 1/2 |
U 1/2 |
22 |
22.75 |
20.4 |
64.0 |
10 3/4 |
V |
|
|
20.6 |
64.6 |
11 |
V 1/2 |
23 |
|
20.8 |
65.2 |
11 1/4 |
W |
|
25 |
21.0 |
65.9 |
11 1/2 |
W 1/2 |
24 |
|
21.2 |
66.5 |
11 3/4 |
X |
|
|
21.4 |
67.2 |
12 |
X 1/2 |
25 |
27.50 |
21.6 |
67.8 |
12 1/4 |
Y |
|
|
21.8 |
68.4 |
12 1/2 |
Z |
26 |
28.75 |
22.0 |
69.1 |
12 3/4 |
Z 1/2 |
|
|
22.2 |
69.7 |
13 |
|
27 |
|
22.4 |
70.3 |
13 1/4 |
Z1 |
|
|
22.6 |
71.0 |
13 1/2 |
|
|
|
22.8 |
71.6 |
13 3/4 |
Z2 |
|
|
23.0 |
72.3 |
14 |
Z3 |
|
|
23.2 |
72.9 |
14 1/4 |
|
|
|
23.4 |
73.5 |
14 1/2 |
Z4 |
|
|
23.6 |
74.2 |
14 3/4 |
|
|
|
23.8 |
74.8 |
15 |
|
|
|
24.0 |
75.4 |
15 1/4 |
|
|
|
24.2 |
76.1 |
15 1/2 |
|
|
|
24.4 |
76.7 |
15 3/4 |
|
|
|
24.6 |
77.4 |
16 |
|
|
|
|