my forever diamond international ring size chart

UK
diameter
mm
circumference
mm
American
A
11.5
36.25
0.5
B
12.3
38.64
1
C
12.7
39.90
1.5
D
13.1
41.15
2
E
13.5
42.41
2.5
F
13.9
43.67
3
G
14.3
44.92
3.25
H
14.7
46.18
3.75
I
15.1
47.44
4.25
J
15.5
48.69
4.75
K
15.9
49.95
5.25
L
16.3
51.24
5.75
M
16.7
52.46
6.25
N
17.1
53.72
6.75
O
17.5
54.98
7
P
17.9
56.23
7.5
Q
18.3
57.49
8
R
18.7
58.75
8.5
S
19.1
60.00
9
T
19.5
61.26
9.5
U
19.9
62.52
10
V
20.3
63.77
10.5
W
20.7
65.00
11
X
21.1
66.29
11.5
Y
21.5
67.51
12
Z
21.9
68.77
12.5
Z+1
22.3
69.99
Z+2
22.7
71.31
Z+3
23.1
72.57
Z+4
23.5
73.83
Z+5
23.9
75.08
Z+6
24.3
76.34
Z+7
24.7
77.60
Z+8
25.1
78.86

To calculate:
American size= (diameter-11.54)/(0.83)
Japanese size= (diameter-12.67)*3
European size= circumference-40



USA
inches
mm
4
1.8307"
46.5
4 1/2
1.8818"
47.8
5
1.9291"
49.0
5 1/2
1.9803"
50.3
6
2.0275"
51.5
6 1/2
2.0787"
52.8
7
2.1259"
54.0
7 1/2
2.1771"
55.3
8
2.2283"
56.6
8 1/2
2.2755"
57.8
9
2.3267"
59.1
9 1/2
2.3740"
60.3
10
2.4251"
61.6
10 1/2
2.4724"
62.8
11
2.5236"
64.1
11 1/2
2.5708"
65.3
12
2.6220"
66.6
12 1/2
2.6732"
67.9
13
2.7204"
69.1

 

USA & Canada
diameter inches
Great Britain
France mm
Germany
Japan
Switzerland
000
0.390
---
---
---
---
---
00
0.422
---
---
---
---
---
0
0.454
---
---
---
---
---
1/2
0.462
A
---
---
---
---
3/4
0.471
A-1/2
---
---
---
---
1
0.487
B
---
---
1
---
1 1/4
0.495
B-1/2
---
---
---
---
1 1/2
0.503
C
---
---
---
---
1 3/4
0.511
C-1/2
---
---
---
---
2
0.520
D
41 1/2
13 1/4
2
1 1/2
2 1/4
0.528
D-1/2
42 1/8
13 1/2
---
---
2 1/2
0.536
E
42 3/4
13 3/4
3
2 3/4
2 3/4
0.544
E-1/2
43 3/8
---
---
3 3/8
3
0.553
F
44
14
4
4
3 1/4
0.561
F-1/2
44 5/8
14 1/4
---
4 5/8
3 1/2
0.569
G
45 1/4
14 1/2
5
5 1/4
3 3/4
0.577
G-1/2
45 7/8
14 3/4
6
5 7/8
4
0.586
H-1/2
46 1/2
15
7
6 1/2
4 1/4
0.594
I
47 1/8
15 1/4
---
7 1/8
4 1/2
0.602
I-1/2
47 3/4
15 1/2
8
7 3/4
4 3/4
0.610
J
48 3/8
---
---
8 3/8
5
0.619
J-1/2
49
15 3/4
9
9
5 1/4
0.627
K
49 5/8
16
---
9 5/8
5 1/2
0.635
K-1/2
50 1/4
16 1/4
10
10 1/4
5 3/4
0.643
L
50 7/8
---
11
10 7/8
6
0.652
L-1/2
51 1/2
16 1/2
12
11 1/2
6 1/4
0.660
M
52 1/8
16 3/4
---
12 1/8
6 1/2
0.668
M-1/2
52 3/4
17
13
12 3/4
6 3/4
0.676
N
53 3/8
---
---
13 3/8
7
0.685
O
54
17 1/4
14
14
7 1/4
0.693
O-1/2
54 5/8
17 1/2
---
14 5/8
7 1/2
0.701
P
55 1/4
17 3/4
15
15 1/4
7 3/4
0.709
P-1/2
55 7/8
---
---
15 7/8
8
0.717
Q
56 1/2
18
16
16 1/2
8 1/4
0.726
Q-1/2
57 1/8
18 1/4
---
17 1/8
8 1/2
0.734
R
57 3/4
18 1/2
17
17 3/4
8 3/4
0.742
R-1/2
58 3/8
18 3/4
---
18 3/8
9
0.750
S
59
19
18
19
9 1/4
0.759
S-1/2
59 5/8
19 1/4
---
19 5/8
9 1/2
0.767
---
60 1/4
19 1/2
19
20 1/4
9 3/4
0.775
T
60 7/8
19 3/4
---
20 7/8
10
0.783
T-1/2
61 1/2
20
20
21 1/2
10 1/4
0.792
U
62 1/8
20 1/4
21
22 1/8
10 1/2
0.800
U-1/2
62 3/4
20 1/2
22
22 3/4
10 3/4
0.808
V
63 3/8
---
---
23 3/8
11
0.816
V-1/2
64
20 3/4
23
24
11 1/4
0.825
W
64 5/8
---
---
24 5/8
11 1/2
0.833
W-1/2
65 1/4
21
24
25 1/4
11 3/4
0.841
X
65 7/8
---
---
25 7/8
12
0.849
Y
66 1/2
21 1/4
25
26 1/2
12 1/4
0.858
Y-1/2
67 1/8
21 1/2
---
27 1/8
12 1/2
0.866
Z
67 3/4
21 3/4
26
27 3/4
12 3/4
0.874
Z-1/2
68 3/8
---
---
28 3/8
13
0.882
---
69
22
27
29

 

 

measure ring size with a finger strip chart

To create your own ring sizer, print and cut the strip below. Insert the narrow end of the sizer through the "cut here" slot. With numbers on the outside, place the loop around your finger, and pull until the fit is snug but comfortable.
In order to print the ring sizer on this page, be sure that your printer is set to 100%.

finger size strip

 

inches
mm
US
British
French
German
Swiss
Japanese
Hong Kong
1 3/4
44.5
3
F
44
14
4
4
6
1 25/32
45.2
3 1/2
G
45
14.5
5 1/2
6
8
1 13/16
46
4
H
47
15
7
7
8.5
1 7/8
47.6
4 1/2
I
48
15.5
9
8
9.5
1 15/16
49.2
5
J
50
15.8
10
9
10.5
2
50.8
5 1/2
K
52
16
12
10
11.5
2 1/16
52.4
6
L
53
16.5
13
12
13.5
2 3/32
53.2
6 1/2
M
54
17
14
13
14.5
2 1/8
54
7
N
55
17.3
15
14
15.5
2 3/16
55.6
7 1/2
O
57
17.8
16 1/2
15
16.5
2 1/4
57.2
8
P
58
18
18
16
17.5
2 5/32
54.8
8 1/2
Q
59
18.5
19
17
18
2 5/16
58.7
9
R
60
19
20
18
19
2 3/8
60.3
9 1/2
S
61
19.5
21 1/2
19
20
2 7/16
61.9
10
T
62
20.3
22
20
21
2 1/2
63.5
10 1/2
U
63
20.8
23 1/2
22
23
2 9/16
65.1
11
W
64
21
25
23
24
2 19/32
65.9
11 1/2
X
66
21.3
26
24
25
2 5/8
66.7
12
Y
67
21.8
27 1/2
25
26
2 11/16
68.3
12 1/2
Z
69
22
29
26
27
2 3/4
69.9
13
--
--
--
--
27
28