Measurement Guidance
Ring Size
OR Use the table below together with a piece of string/shoe lace and a ruler (or just a Soft Tape Measure)
Circumference
Diameter
UK / Australia / NZ
US / Canada / Mexico
Europe / ISO 8653 / Russia
Japan / China / South America
Switzerland / Germany
37.8 mm
12.03 mm
A
0½
38
1
-
38.42 mm
12.23 mm
A½
0¾
39.05 mm
12.43 mm
B
1
39
39.67 mm
12.63 mm
B½
1¼
40
40.3 mm
12.83 mm
C
1½
40.92 mm
13.03 mm
C½
1¾
41
1
41.55 mm
13.23 mm
D
2
42
2
1.5
42.17 mm
13.42 mm
D½
2¼
2
42.8 mm
13.62 mm
E
2½
43
3
3
43.42 mm
13.82 mm
E½
2¾
3.5
44.05 mm
14.02 mm
F
3
44
4
4
44.67 mm
14.22 mm
F½
3¼
45
5
4.5
45.3 mm
14.42 mm
G
3½
5.5
45.92 mm
14.62 mm
G½
3¾
46
6
6
46.55 mm
14.82 mm
H
4
47
6.5
47.17 mm
15.02 mm
H½
4¼
7
7
47.8 mm
15.22 mm
I
4½
48
8
8
48.42 mm
15.41 mm
I½
4¾
8.5
49.05 mm
15.61 mm
J
5
49
9
9
49.67 mm
15.81 mm
J½
5¼
50
9.5
50.3 mm
16.01 mm
K
5½
10
10.5
50.92 mm
16.21 mm
K½
5¾
51
11
11
51.55 mm
16.41 mm
L
6
52
11.5
52.17 mm
16.61 mm
L½
12
12
52.8 mm
16.81 mm
M
6¼
53
13
53.42 mm
17.01 mm
M½
6½
13
13.5
54.05 mm
17.2 mm
N
6¾
54
14
14
54.67 mm
17.4 mm
N½
7
55
14.5
55.3 mm
17.6 mm
O
7¼
15
15.5
55.92 mm
17.8 mm
O½
7½
56
16
56.55 mm
18 mm
P
7¾
57
16
16.5
57.17 mm
18.2 mm
P½
8
17
17
57.8 mm
18.4 mm
Q
8¼
58
18
58.42 mm
18.6 mm
Q½
8½
18
18.5
59.05 mm
18.8 mm
R
8¾
59
19
59.67 mm
19 mm
R½
9
60
19
19.5
60.3 mm
19.19 mm
S
9¼
20
20.5
60.92 mm
19.39 mm
S½
9½
61
21
61.55 mm
19.59 mm
T
9¾
62
21
21.5
62.17 mm
19.79 mm
T½
10
22
62.8 mm
19.99 mm
U
10¼
63
22
23
63.42 mm
20.19 mm
U½
10½
23
23.5
64.05 mm
20.39 mm
V
10¾
64
24
64.67 mm
20.59 mm
V½
11
65
24
24.5
65.3 mm
20.79 mm
W
11¼
25.5
65.92 mm
20.98 mm
W½
11½
66
25
26
66.55 mm
21.18 mm
X
11¾
67
26
26.5
67.17 mm
21.38 mm
X½
12
27
67.8 mm
21.58 mm
Y
12¼
68
27
28
68.42 mm
21.78 mm
Y½
12½
28.5
69.05 mm
21.98 mm
Z
12¾
69
28
29
69.67 mm
22.18 mm
Z½
13
70
29
29.5
70.3 mm
22.38 mm
Z+1
13¼
30.5
70.92 mm
22.58 mm
Z+1½
13½
71
30
31
71.55 mm
22.78 mm
Z+2
13¾
72
31.5
72.17 mm
22.97 mm
Z+2½
14
31
32
72.8 mm
23.17 mm
Z+3
14¼
73
32
33
73.42 mm
23.37 mm
Z+3½
14½
33.5
74.05 mm
23.57 mm
Z+4
14¾
74
33
34
74.67 mm
23.77 mm
Z+4½
15
75
34.5
75.3 mm
23.97 mm
Z+5
15¼
34
35.5
75.92 mm
24.17 mm
Z+5½
15½
76
35
36
76.55 mm
24.37 mm
Z+6
15¾
77
36.5
77.17 mm
24.57 mm
Z+6½
16
36
37
77.8 mm
24.76 mm
Z+7
16¼
78
38
78.42 mm
24.96 mm
Z+7½
16½
37
38.5
79.05 mm
25.16 mm
Z+8
16¾
79
39
79.67 mm
25.36 mm
Z+8½
17
80
38
39.5
80.3 mm
25.56 mm
Z+9
17¼
39
40.5
80.92 mm
25.76 mm
Z+9½
17½
81
41
81.55 mm
25.96 mm
Z+10
17¾
82
40
41.5
82.17 mm
26.16 mm
Z+10½
42
82.8 mm
26.36 mm
Z+11
18
83
41
43
83.42 mm
26.56 mm
Z+11½
18¼
42
43.5
84.05 mm
26.75 mm
Z+12
18½
84
44
84.67 mm
26.95 mm
Z+12½
18¾
85
43
44.5
85.3 mm
27.15 mm
Z+13
19
45.5
85.92 mm
27.35 mm
Z+13½
19¼
86
44
46
86.55 mm
27.55 mm
Z+14
19½
87
45
46.5
87.17 mm
27.75 mm
Z+14½
19¾
47
87.8 mm
27.95 mm
Z+15
20
88
46
48
88.42 mm
28.15 mm
Z+15½
20¼
48.5
89.05 mm
28.35 mm
Z+16
20½
89
47
49
89.67 mm
28.54 mm
Z+16½
20¾
90
48
49.5
90.3 mm
28.74 mm
Z+17
21
50.5
90.92 mm
28.94 mm
Z+17½
21¼
91
49
51
91.55 mm
29.14 mm
Z+18
21½
92
51.5
92.17 mm
29.34 mm
Z+18½
21¾
50
52
92.8 mm
29.54 mm
Z+19
22
93
51
53
93.42 mm
29.74 mm
Z+19½
22¼
53.5
94.05 mm
29.94 mm
Z+20
22½
94
52
54
Inch to MM
| Inch | ||||
| Inch Fraction | / | |||
| MM | ||||
| CM |
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