Masonic Rings - International Ring Size Conversion
International Ring Size Conversion Table
| US Size |
Dia. -inch |
Dia. in MM |
Metric -MM |
British |
French |
German |
Japanese |
Swiss |
| 6 |
.650 |
16.51 |
51.5 |
M |
52 3/4 |
16 1/2 |
12 |
12 3/4 |
| 6 1/4 |
- |
16.71 |
52.2 |
M 1/2 |
- |
|
|
|
| 6 1/2 |
.666 |
16.92 |
52.8 |
N |
54 |
17 |
13 |
14 |
| 6 3/4 |
- |
17.13 |
53.4 |
N 1/2 |
- |
|
|
|
| 7 |
.683 |
17.35 |
54.0 |
O |
55 1/4 |
17 1/4 |
14 |
15 1/4 |
| 7 1/4 |
- |
17.45 |
54.7 |
O 1/2 |
- |
|
|
|
| 7 1/2 |
.699 |
17.75 |
55.3 |
P |
56 1/2 |
17 3/4 |
15 |
16 1/2 |
| 7 3/4 |
- |
17.97 |
55.9 |
P 1/2 |
- |
|
|
|
| 8 |
.716 |
18.19 |
56.6 |
Q |
57 3/4 |
18 |
16 |
17 3/4 |
| 8 1/4 |
- |
18.35 |
57.2 |
Q 1/2 |
- |
|
|
|
| 8 1/2 |
.732 |
18.53 |
57.8 |
- |
- |
18 1/2 |
17 |
|
| 8 5/8 |
- |
18.61 |
58.4 |
R |
59 |
|
|
19 |
| 8 3/4 |
- |
18.69 |
58.4 |
- |
- |
|
|
|
| 8 7/8 |
- |
18.80 |
59.0 |
R 1/2 |
- |
|
|
|
| 9 |
.748 |
18.89 |
59.1 |
- |
- |
19 |
18 |
|
| 9 1/8 |
- |
19.10 |
59.4 |
S |
60 1/4 |
|
|
20 1/4 |
| 9 1/4 |
- |
19.22 |
59.7 |
- |
- |
|
|
|
| 9 3/8 |
- |
19.31 |
60.0 |
S 1/2 |
- |
|
|
|
| 9 1/2 |
.764 |
19.41 |
60.3 |
- |
- |
19 1/2 |
19 |
|
| 9 5/8 |
- |
19.51 |
60.6 |
T |
61 1/2 |
|
|
21 1/2 |
| 9 3/4 |
- |
19.62 |
60.9 |
- |
- |
|
|
|
| 10 |
.781 |
19.84 |
61.6 |
T 1/2 |
- |
20 |
20 |
|
| 10 1/4 |
- |
20.02 |
62.2 |
U |
62 3/4 |
|
21 |
22 3/4 |
| 10 1/2 |
.797 |
20.20 |
62.8 |
U 1/2 |
- |
20 1/4 |
22 |
|
| 10 5/8 |
- |
20.32 |
63.1 |
V |
63 |
|
|
23 3/4 |
| 10 3/4 |
- |
20.44 |
63.5 |
- |
- |
|
|
|
| 11 |
.814 |
20.68 |
64.1 |
V 1/2 |
- |
20 3/4 |
23 |
|
| 11 1/8 |
- |
20.76 |
64.3 |
W |
65 |
|
|
25 |
| 11 1/4 |
- |
20.85 |
64.7 |
- |
- |
|
|
|
| 11 3/8 |
- |
20.94 |
65.0 |
W 1/2 |
- |
|
|
|
| 11 1/2 |
- |
21.08 |
65.3 |
- |
- |
21 |
24 |
|
| 11 5/8 |
.830 |
21.18 |
65.7 |
X |
66 1/4 |
|
|
26 1/4 |
| 11 3/4 |
- |
21.24 |
66.0 |
- |
- |
|
|
|
| 11 7/8 |
- |
21.30 |
66.3 |
X 1/2 |
- |
|
|
|
| 12 |
.846 |
21.49 |
66.6 |
Y |
67 1/2 |
21 1/4 |
25 |
27 1/2 |
| 12 1/4 |
- |
21.69 |
67.2 |
Y 1/2 |
- |
|
|
|
| 12 1/2 |
.862 |
21.89 |
67.9 |
Z |
68 3/4 |
21 3/4 |
26 |
28 3/4 |
| 12 3/4 |
- |
22.10 |
68.5 |
Z 1/2 |
- |
|
|
|
| 13 |
.879 |
22.33 |
69.1 |
- |
- |
22 |
27 |
|