Ring Size Conversion
| Inner Diameter (mm) |
United States |
Europe |
Japan |
| 14.1 |
3 |
F |
4 |
| 14.3 |
3.25 |
F 1/2 |
5 |
| 14.5 |
3.5 |
G |
|
| 14.7 |
3.75 |
G 1/2 |
6 |
| 14.9 |
4 |
H |
7 |
| 15.1 |
4.25 |
H 1/2 |
|
| 15.3 |
4.5 |
I |
8 |
| 15.5 |
4.75 |
J |
|
| 15.7 |
5 |
J 1/2 |
9 |
| 15.9 |
5.25 |
K |
|
| 16.1 |
5.5 |
K 1/2 |
10 |
| 16.3 |
5.75 |
L |
|
| 16.5 |
6 |
L 1/2 |
11 |
| 16.7 |
6.25 |
M |
12 |
| 16.9 |
6.5 |
M 1/2 |
13 |
| 17.1 |
6.75 |
N |
|
| 17.3 |
7 |
M 1/2 |
14 |
| 17.5 |
7.25 |
O |
|
| 17.7 |
7.5 |
O 1/2 |
15 |
| 17.9 |
7.75 |
P |
|
| 18.1 |
8 |
P 1/2 |
16 |
| 18.3 |
8.25 |
Q |
|
| 18.5 |
8.5 |
Q 1/2 |
17 |
| 18.8 |
8.75 |
R |
|
| 19.0 |
9 |
R 1/2 |
18 |
| 19.2 |
9.25 |
S |
|
| 19.4 |
9.5 |
S 1/2 |
19 |
| 19.6 |
9.75 |
T |
|
| 19.8 |
10 |
T 1/2 |
20 |
| 20.0 |
10.25 |
U |
21 |
| 20.2 |
10.5 |
U 1/2 |
22 |
| 20.4 |
10.75 |
V |
|
| 20.6 |
11 |
V 1/2 |
23 |
| 20.8 |
11.25 |
W |
|
| 21.0 |
11.5 |
W 1/2 |
24 |
| 21.2 |
11.75 |
X |
|
| 21.4 |
12 |
X 1/2 |
25 |
