This ring size conversion chart will easily allow one to convert a ring size between the US, British, French, German, Japanese, and Swiss Standards.
Additionally, it will also allow one to determine the ring size of an existing ring by measuring the diameter in either millimeters or inches.
|
US Size |
Diameter (Inches) |
Diameter (MM) |
Metric MM Equivalent |
British |
French |
German |
Japanese |
Swiss |
|---|---|---|---|---|---|---|---|---|
|
0000 |
.390 |
9.91 |
- |
|||||
|
00 |
.422 |
10.72 |
- |
|||||
|
0 |
.454 |
11.53 |
- |
|||||
|
1/2 |
.474 |
11.95 |
A |
|||||
|
3/4 |
.482 |
12.18 |
A 1/2 |
|||||
|
1 |
.487 |
12.37 |
38.9 |
B |
1 |
|||
|
1 1/4 |
- |
12.60 |
39.6 |
B 1/2 |
||||
|
1 1/2 |
.503 |
12.78 |
40.2 |
C |
||||
|
1 3/4 |
- |
13.00 |
40.8 |
C 1/2 |
||||
|
2 |
.520 |
13.21 |
41.5 |
D |
41 1/2 |
13 1/2 |
2 |
1 1/2 |
|
2 1/4 |
- |
13.41 |
42.1 |
D 1/2 |
- |
- |
||
|
2 1/2 |
.536 |
13.61 |
42.7 |
E |
42 3/4 |
13 3/4 |
3 |
2 3/4 |
|
2 3/4 |
- |
13.83 |
43.4 |
E 1/2 |
- |
- |
||
|
3 |
.553 |
14.05 |
44.0 |
F |
44 |
14 |
4 |
4 |
|
3 1/8 |
- |
14.15 |
44.3 |
F 1/2 |
- |
- |
||
|
3 1/4 |
- |
14.25 |
44.6 |
- |
- |
- |
||
|
3 3/8 |
- |
14.36 |
44.9 |
G |
45 1/4 |
- |
5 |
5 1/4 |
|
3 1/2 |
.569 |
14.45 |
45.2 |
- |
- |
14 1/2 |
||
|
3 5/8 |
- |
14.56 |
45.6 |
G 1/2 |
- |
6 |
||
|
3 3/4 |
- |
14.65 |
45.9 |
H |
46 1/2 |
6 1/2 |
||
|
4 |
.585 |
14.86 |
46.5 |
H 1/2 |
- |
15 |
7 |
|
|
4 1/4 |
- |
15.04 |
47.1 |
I |
47 3/4 |
7 3/4 |
||
|
4 1/2 |
.601 |
15.27 |
47.8 |
I 1/2 |
- |
15 1/4 |
8 |
|
|
4 5/8 |
- |
15.40 |
48.1 |
J |
49 |
15 1/2 |
9 |
|
|
4 3/4 |
- |
15.53 |
48.4 |
- |
- |
|||
|
5 |
.618 |
15.70 |
49.0 |
J 1/2 |
- |
15 3/4 |
9 |
|
|
5 1/8 |
- |
15.80 |
49.3 |
K |
50 |
10 |
||
|
5 1/4 |
- |
15.90 |
49.6 |
- |
- |
|||
|
5 3/8 |
- |
16.0 |
50.0 |
K 1/2 |
- |
10 |
||
|
5 1/2 |
.634 |
16.10 |
50.3 |
L |
51 3/4 |
16 |
11 3/4 |
|
|
5 3/4 |
- |
16.30 |
50.9 |
- |
- |
|||
|
5 7/8 |
- |
16.41 |
51.3 |
L 1/2 |
- |
|||
|
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 |