How to Measure Ring Size
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VIDEO
International Ring Size Conversion Chart
by The Official International Ring Size Guide
Inside Diameter
Inside Circumference
Sizes
MM
Inches
MM
Inches
British & Australian
US & Canada
French & Russian
German
Japanese
Swiss
9.91
0.390
31.13
1.22
–
0000
–
–
–
–
10.72
0.442
33.68
1.39
–
00
–
–
–
–
11.53
0.454
36.22
1.43
–
0
–
–
–
–
11.95
0.474
37.54
1.49
A
1/2
–
–
–
–
12.18
0.482
38.26
1.51
A 1/2
3/4
–
–
–
–
12.37
0.487
38.86
1.53
B
1
–
–
1
–
12.60
0.496
39.58
1.56
B 1/2
1 1/4
–
–
–
–
12.78
0.503
40.15
1.58
C
1 1/2
–
–
–
–
13.00
0.512
40.84
1.61
C 1/2
1 3/4
–
–
–
–
13.21
0.520
41.50
1.63
D
2
41 1/2
13 1/2
2
1 1/2
13.41
0.528
42.13
1.66
D 1/2
2 1/4
–
–
–
–
13.61
0.536
42.76
1.68
E
2 1/2
42 3/4
13 3/4
3
2 3/4
13.83
0.544
43.45
1.71
E 1/2
2 3/4
–
–
–
–
14.05
0.553
44.14
1.74
F
3
44
14
4
4
14.15
0.557
44.45
1.75
F 1/2
3 1/8
–
–
–
–
14.25
0.561
44.77
1.76
F 3/4
3 1/4
–
–
–
–
14.36
0.565
45.11
1.77
G
3 3/8
45 1/4
–
5
5 1/4
14.45
0.569
45.40
1.79
G 1/4
3 1/2
–
14 1/2
–
–
14.56
0.573
45.74
1.80
G 1/2
3 5/8
–
–
6
–
14.65
0.577
46.02
1.81
H
3 3/4
46 1/2
–
–
6 1/2
14.86
0.585
46.68
1.84
H 1/2
4
–
15
7
–
15.04
0.592
47.25
1.86
I
4 1/4
47 3/4
–
–
7 3/4
15.27
0.601
47.97
1.89
I 1/2
4 1/2
–
15 1/4
8
–
15.40
0.606
48.38
1.90
J
4 5/8
49
15 1/2
–
9
15.53
0.611
48.79
1.92
J 1/4
4 3/4
–
–
–
–
15.70
0.618
49.32
1.94
J 1/2
5
–
15 3/4
9
–
15.80
0.622
49.64
1.95
K
5 1/8
50
–
–
10
15.90
0.626
49.95
1.97
K 1/4
5 1/4
–
–
–
–
16.00
0.630
50.27
1.98
K 1/2
5 3/8
–
–
10
–
16.10
0.634
50.58
1.99
L
5 1/2
51 3/4
16
–
11 3/4
16.30
0.642
51.21
2.02
L 1/4
5 3/4
–
–
–
–
16.41
0.646
51.55
2.03
L 1/2
5 7/8
–
–
–
–
16.51
0.650
51.87
2.04
M
6
52 3/4
16 1/2
12
12 3/4
16.71
0.658
52.50
2.07
M 1/2
6 1/4
–
–
–
–
16.92
0.666
53.16
2.09
N
6 1/2
54
17
13
14
17.13
0.674
53.82
2.12
N 1/2
6 3/4
–
–
–
–
17.35
0.683
54.51
2.15
O
7
55 1/4
17 1/4
14
15 1/4
17.45
0.687
54.82
2.16
O 1/2
7 1/4
–
–
–
–
17.75
0.699
55.76
2.20
P
7 1/2
56 1/2
17 3/4
15
16 1/2
17.97
0.707
56.45
2.22
P 1/2
7 3/4
–
–
–
–
18.19
0.716
57.15
2.25
Q
8
57 3/4
18
16
17 3/4
18.35
0.722
57.65
2.27
Q 1/2
8 1/4
–
–
–
–
18.53
0.729
58.21
2.29
Q 3/4
8 1/2
–
18 1/2
17
–
18.61
0.733
58.47
2.30
R
8 5/8
59
–
–
19
18.69
0.736
58.72
2.31
R 1/4
8 3/4
–
–
–
–
18.80
0.740
59.06
2.32
R 1/2
8 7/8
–
–
–
–
18.89
0.748
59.34
2.35
R 3/4
9
–
19
18
–
19.10
0.752
60.00
2.36
S
9 1/8
60 1/4
–
–
20 1/4
19.22
0.757
60.38
2.38
S 1/4
9 1/4
–
–
–
–
19.31
0.760
60.66
2.39
S 1/2
9 3/8
–
–
–
–
19.41
0.764
60.98
2.40
S 3/4
9 1/2
–
19 1/2
19
–
19.51
0.768
61.29
2.41
T
9 5/8
61 1/2
–
–
21 1/2
19.62
0.772
61.64
2.43
T 1/4
9 3/4
–
–
–
–
19.84
0.781
62.33
2.45
T 1/2
10
–
20
20
–
20.02
0.788
62.89
2.48
U
10 1/4
62 3/4
–
21
22 3/4
20.20
0.797
63.46
2.50
U 1/2
10 1/2
–
20 1/4
22
–
20.32
0.800
63.84
2.51
V
10 5/8
63
–
–
23 3/4
20.44
0.805
64.21
2.53
V 1/4
10 3/4
–
–
–
–
20.68
0.814
64.97
2.56
V 1/2
11
–
20 3/4
23
–
20.76
0.817
65.22
2.57
W
11 1/8
65
–
–
25
20.85
0.821
65.50
2.58
W 1/4
11 1/4
–
–
–
–
20.94
0.824
65.78
2.59
W 1/2
11 3/8
–
–
–
–
21.08
0.830
66.22
2.61
W 3/4
11 1/2
–
21
24
–
21.18
0.834
66.54
2.62
X
11 5/8
66 1/4
–
–
26 1/4
21.24
0.836
66.73
2.63
X 1/4
11 3/4
–
–
–
–
21.30
0.839
66.92
2.64
X 1/2
11 7/8
–
–
–
–
21.49
0.846
67.51
2.66
Y
12
67 1/2
21 1/4
25
27 1/2
21.69
0.854
68.14
2.68
Y 1/2
12 1/4
–
–
–
–
21.89
0.862
68.77
2.71
Z
12 1/2
68 3/4
21 3/4
26
28 3/4
22.10
0.870
69.43
2.73
Z +1/2
12 3/4
–
–
–
–
22.33
0.879
70.15
2.76
Z+1
13
–
22
27
–
22.60
0.890
71.00
2.80
Z+1.5
13.5
–
–
–
–
22.69
0.893
71.28
2.81
Z+2
–
–
–
–
–
22.92
0.902
72.00
2.83
Z+2.5
–
–
–
–
–
23.06
0.908
72.45
2.85
Z+3
–
–
–
–
–
23.24
0.915
73.01
2.87
Z+3.5
–
–
–
–
–
23.47
0.924
73.73
2.90
Z+4
–
–
–
–
–
23.55
0.927
73.98
2.91
Z+4.5
–
–
–
–
–
23.87
0.940
74.99
2.95
Z+5
–
–
–
–
–
24.27
0.956
76.25
3.00
Z+6
–
–
–
–
–