International Ring Size Conversion Chart
Circumference (mm)
Europe / ISO |
Diameter (mm) |
USA / Canada |
UK / Australia |
Asia |
Switzerland |
| 44.2 |
14.1 |
3 |
F |
4 |
4 |
| 44.8 |
14.3 |
|
F-1/2 |
5 |
5-1/4 |
| 45.5 |
14.5 |
3-1/2 |
G |
|
|
| 46.1 |
14.7 |
|
G-1/2 |
6 |
6-1/2 |
| 46.8 |
14.9 |
4 |
H |
7 |
|
| 47.4 |
15.1 |
|
H-1/2 |
|
7-3/4 |
| 48.0 |
15.3 |
4-1/2 |
I |
8 |
|
| 48.7 |
15.5 |
|
J |
|
9 |
| 49.3 |
15.7 |
5 |
J-1/2 |
9 |
|
| 50.0 |
15.9 |
|
K |
|
10 |
| 50.6 |
16.1 |
5-1/2 |
K-1/2 |
10 |
|
| 51.2 |
16.3 |
|
L |
|
11-3/4 |
| 51.9 |
16.5 |
6 |
L-1/2 |
11 |
12-3/4 |
| 52.5 |
16.7 |
|
M |
12 |
|
| 53.1 |
16.9 |
6-1/2 |
M-1/2 |
13 |
14 |
| 53.8 |
17.1 |
|
N |
|
|
| 54.4 |
17.3 |
7 |
N-1/2 |
14 |
15-1/4 |
| 55.1 |
17.5 |
|
O |
|
|
| 55.7 |
17.7 |
7-1/2 |
O-1/2 |
15 |
16-1/2 |
| 56.3 |
17.9 |
|
P |
|
|
| 57.0 |
18.1 |
8 |
P-1/2 |
16 |
17-3/4 |
| 57.6 |
18.3 |
|
Q |
|
|
| 58.3 |
18.5 |
8-1/2 |
Q-1/2 |
17 |
|
| 58.9 |
18.8 |
|
R |
|
19 |
| 59.5 |
19.0 |
9 |
R-1/2 |
18 |
|
| 60.2 |
19.2 |
|
S |
|
20-1/4 |
| 60.8 |
19.4 |
9-1/2 |
S-1/2 |
19 |
|
| 61.4 |
19.6 |
|
T |
|
21-1/2 |
| 62.1 |
19.8 |
10 |
T-1/2 |
20 |
|
| 62.7 |
20.0 |
|
U |
21 |
|
| 63.4 |
20.2 |
10-1/2 |
U-1/2 |
22 |
22-3/4 |
| 64.0 |
20.4 |
|
V |
|
|
| 64.6 |
20.6 |
11 |
V-1/2 |
23 |
|
| 65.3 |
20.8 |
|
W |
|
25 |
| 65.9 |
21.0 |
11-1/2 |
W-1/2 |
24 |
|
| 66.6 |
21.2 |
|
X |
|
|
| 67.2 |
21.4 |
12 |
X-1/2 |
25 |
27-1/2 |
| 67.8 |
21.6 |
|
Y |
|
|
| 68.5 |
21.8 |
12-1/2 |
Z |
26 |
28-3/4 |
| 69.1 |
22.0 |
|
Z-1/2 |
|
|
| 69.7 |
22.2 |
13 |
|
27 |
|
| 70.4 |
22.4 |
|
Z + 1 |
|
|
| 71.0 |
22.6 |
13-1/2 |
|
|
|
|
|
