Convert your ring size to the ring size used in other countries.
USA size
Diam. inch.
Diam. mm
Circum. mm
0000
00
0
1/2
3/4
1
1 1/4
1 1/2
1 3/4
2
2 1/4
2 1/2
2 3/4
3
3 1/8
3 1/4
3 3/8
3 1/2
3 5/8
3 3/4
4
4 1/4
4 1/2
4 5/8
4 3/4
5
5 1/8
5 1/4
5 3/8
5 1/2
5 3/4
5 7/8
6
6 1/4
6 1/2
6 3/4
7
7 1/4
7 1/2
7 3/4
8
8 1/4
8 1/2
8 5/8
8 3/4
8 7/8
9
9 1/8
9 1/4
9 3/8
9 1/2
9 5/8
9 3/4
10
10 1/4
10 1/2
10 5/8
10 3/4
11
11 1/8
11 1/4
11 3/8
11 1/2
11 5/8
11 3/4
11 7/8
12
12 1/2
12 3/4
13
.390
.422
.454
.474
.482
.487
---
.503
---
.520
---
.536
---
.553
---
---
---
.569
---
---
.585
---
.601
---
---
.618
---
---
---
.634
---
---
.650
---
.666
---
.683
---
.699
---
.716
---
.732
---
---
---
.748
---
---
---
.764
---
---
.781
---
.797
---
---
.814
---
---
---
---
.830
---
---
.846
.862
---
.879
9.91
10.72
11.53
11.95
12.18
12.37
12.60
12.78
13.00
13.21
13.41
13.61
13.83
14.05
14.15
14.25
14.36
14.45
14.56
14.65
14.86
15.04
15.27
15.40
15.53
15.70
15.80
15.90
16.0
16.10
16.30
16.41
16.51
16.71
16.92
17.13
17.35
17.45
17.75
17.97
18.19
18.35
18.53
18.61
18.69
18.80
18.89
19.10
19.22
19.31
19.41
19.51
19.62
19.84
20.02
20.20
20.32
20.44
20.68
20.76
20.85
20.94
21.08
21.18
21.24
21.30
21.49
21.89
22.10
22.33
31.1
33.7
36.2
37.5
38.3
38.9
39.6
40.2
40.8
41.5
42.1
42.7
43.4
44.0
44.3
44.6
44.9
45.2
45.6
45.9
46.5
47.1
47.8
48.1
48.4
49.0
49.3
49.6
50.0
50.3
50.9
51.3
51.5
52.2
52.8
53.4
54.0
54.7
55.3
55.9
56.6
57.2
57.8
58.4
58.4
59.0
59.1
59.4
59.7
60.0
60.3
60.6
60.9
61.6
62.2
62.8
63.1
63.5
64.1
64.3
64.7
65.0
65.3
65.7
66.0
66.3
66.6
67.9
68.5
69.1
British
French
German
Japanese
Swiss
---
---
---
A
A 1/2
B
B 1/2
C
C 1/2
D
D 1/2
E
E 1/2
F
F 1/2
---
G
---
G 1/2
H
H 1/2
I
I 1/2
J
---
J 1/2
K
---
K 1/2
L
---
L 1/2
M
M 1/2
N
N 1/2
O
O 1/2
P
P 1/2
Q
Q 1/2
---
R
---
R 1/2
---
S
---
S 1/2
---
T
---
T 1/2
U
U 1/2
V
---
V 1/2
W
---
W 1/2
---
X
---
X 1/2
Y
Z
Z 1/2
---
---
---
---
---
---
---
---
---
---
41 1/2
---
42 3/4
---
44
---
---
45 1/4
---
---
46 1/2
---
47 3/4
---
49
---
---
50
---
---
51 3/4
---
---
52 3/4
---
54
---
55 1/4
---
56 1/2
---
57 3/4
---
---
59
---
---
---
60 1/4
---
---
---
61 1/2
---
---
62 3/4
---
63
---
---
65
---
---
---
66 1/4
---
---
67 1/2
68 3/4
---
---
---
---
---
---
---
---
---
---
---
13 1/2
---
13 3/4
---
14
---
---
---
14 1/2
---
---
15
---
15 1/4
15 1/2
---
15 3/4
---
---
---
16
---
---
16 1/2
---
17
---
17 1/4
---
17 3/4
---
18
---
18 1/2
---
---
---
19
---
---
---
19 1/2
---
---
20
---
20 1/4
---
---
20 3/4
---
---
---
21
---
---
---
21 1/4
21 3/4
---
22
---
---
---
---
---
1
---
---
---
2
---
3
---
4
---
---
5
---
6
---
7
---
8
---
---
9
---
---
10
---
---
---
12
---
13
---
14
---
15
---
16
---
17
---
---
---
18
---
---
---
19
---
---
20
21
22
---
---
23
---
---
---
24
---
---
---
25
26
---
27
---
---
---
---
---
---
---
---
---
1 1/2
---
2 3/4
---
4
---
---
5 1/4
---
---
6 1/2
---
7 3/4
---
9
---
---
10
---
---
11 3/4
---
---
12 3/4
---
14
---
15 1/4
---
16 1/2
---
17 3/4
---
---
19
---
---
---
20 1/4
---
---
---
21 1/2
---
---
22 3/4
---
23 3/4
---
---
25
---
---
---
26 1/4
---
---
27 1/2
28 3/4
---
---
Select a ring size in one category, the rest will change to match.
How to determine your ring size
Wrap a piece of string or a strip of paper around your finger.
Mark the point where the two ends meet.
Measure the string or paper against a ruler to get the circumference of your finger.
Divide that by 3.14 to get the diameter of your finger.
Look up your ring size using the form above.
