United States Standand Comparative Ring-Size Equivalents.

U. S. & Canada British French German Japanese Swiss
4
H - 1/2
15
7
4 1/4
I
47 3/4
7 3/4
4 1/2
I - 1/2
15 1/4
8
4 7/8
J
49
9
5
J - 1/2
15 3/4
9
5 1/8
K
50
10
5 3/8
K - 1/2
10
5 1/2
L
51 3/4
16
11 3/4
5 7/8
L - 1/2
11
6
M
52 3/4
16 1/2
12
12 3/4
6 1/4
M - 1/2
6 1/2
N
54
17
13
14
6 3/4
N - 1/2
7
O
55 1/4
17 1/4
14
15 1/4
7 1/4
O - 1/2
7 1/2
P
56 1/2
17 3/4
15
16 1/2
7 3/4
P - 1/2
8
Q
57 3/4
18
16
17 3/4
8 1/4
Q -1/2
8 1/2
18 1/2
17
8 5/8
R
59
19
8 7/8
R - 1/2
9
19
18
9 1/8
S
60 1/4
20 1/4
9 3/8
S - 1/2
9 1/2
19 1/2
19
9 5/8
T
61 1/2
21 1/2
10
T - 1/2
...
20
20
...
10 1/4
U
62 3/4
... 21
22 3/4
10 1/2
U - 1/2
...
20 1/4
22 ...
10 5/8
V
63 3/4
... ...
23 3/4
11
V - 1/2
...
20 3/4
23 ...
11 1/8
W
65
... ... 25
11 3/8
W - 1/2
... ... ... ...
11 1/2
... ... 21 24 ...
11 5/8
X
66 1/4
... ...
26 1/4
11 7/8
X - 1/2
... ... ... ...
12
Y
67 1/2
21 1/4
25
27 1/2
12 1/4
Y - 1/2
... ... ... ...
12 1/2
Z
68 3/4
21 3/4
26
28 3/4
12 3/4
Z - 1/2
... ... ... ...
13
... ... 22 27 ...