Ring Size Guide: Japan – EU – US/Canada – UK
| JP (号) |
EU (ISO) |
US/CA |
UK |
Diameter (mm) |
Circumference (mm) |
| 1 |
41 |
1.5 |
C |
12.9 |
40.8 |
| 2 |
42 |
2 |
D |
13.2 |
41.5 |
| 3 |
44 |
2.5 |
E |
13.7 |
43 |
| 4 |
46 |
3 |
F |
14 |
44 |
| 5 |
47 |
3.75 |
G |
14.4 |
45.2 |
| 6 |
48 |
4 |
H |
14.7 |
46.1 |
| 7 |
49 |
4.5 |
I |
15 |
47.1 |
| 8 |
50.5 |
5 |
J½ |
15.4 |
48 |
| 9 |
52 |
5.5 |
K½ |
15.7 |
49.3 |
| 10 |
53 |
6 |
L½ |
16 |
50.2 |
| 11 |
54.5 |
6.5 |
M½ |
16.4 |
51.3 |
| 12 |
56 |
7 |
N½ |
16.7 |
52.5 |
| 13 |
57 |
7.5 |
O½ |
17 |
53.4 |
| 14 |
58.5 |
8 |
P½ |
17.4 |
54.7 |
| 15 |
60 |
8.5 |
Q½ |
17.7 |
55.5 |
| 16 |
61 |
9 |
R½ |
18 |
56.5 |
| 17 |
62.5 |
9.5 |
S½ |
18.4 |
57.8 |
| 18 |
64 |
10 |
T½ |
18.7 |
58.6 |
| 19 |
65 |
10.5 |
U½ |
19 |
59.8 |
| 20 |
66 |
11 |
V½ |
19.4 |
60.7 |
| 21 |
67.5 |
11.5 |
W½ |
19.7 |
61.8 |
| 22 |
69 |
12 |
Y |
20 |
62.8 |
| 23 |
70 |
12.5 |
Z |
20.4 |
64.1 |
| 24 |
71 |
13 |
Z+1 |
20.7 |
65 |
| 25 |
72.5 |
13.5 |
Z+3 |
21 |
66 |
|
