Table of international ring size equivalents

North America (including Canada)

Approximative diameter in inches

Equivalent in Great Britain

Equivalent in France

Equivalent in Germany

Equivalent in Japan

Equivalent in Switzerland

000

.390

-

-

-

-

-

00

.422

-

-

-

-

-

0

.454

-

-

-

-

-

1/2

-

A

-

-

-

-

3/4

-

A1/22

-

-

-

-

1

.487

B

-

-

1

-

1 1/4

-

B-1/2

-

-

-

-

1 1/2

.503

C

-

-

-

-

1 3/4

-

C-1/2

-

-

-

-

2

.520

D

41 1/2

13 1/2

2

1 1/2

2 1/4

-

D-1/2

-

-

-

-

2 1/2

.536

E

42 3/4

13 3/4

3

2 3/4

2 3/4

-

E-1/2

-

-

-

-

3

.553

F

44

14

4

4

3 1/8

-

F-1/2

-

-

-

-

3 3/8

-

G

45 1/4

-

5

5 1/4

3 1/2

.569

-

-

14 1/2

-

-

3 5/8

-

G-1/2

-

-

6

-

3 3/4

-

H

46 1/2

-

-

6 1/2

4

.585

H-1/2

-

15

7

-

4 1/4

-

I

47 3/4

-

-

7 3/4

4 1/2

.601

I-1/2

-

15 1/4

8

-

4 7/8

-

J

49

-

-

9

5

.618

J-1/2

-

15 3/4

9

-

5 1/8

-

K

50

-

-

10

5 3/8

-

K-1/2

-

-

10

-

5 1/2

.634

L

51 3/4

16

-

11 3/4

5 7/8

-

L-1/2

-

-

11

-

6

.650

M

52 3/4

16 1/2

12

12 3/4

6 1/4

-

M-1/2

-

-

-

-

6 1/2

.666

N

54

17

13

14

6 3/4

-

N-1/2

-

-

-

7

.683

O

55 1/4

17 1/4

14

15 1/4

7 1/4

-

O-1/2

-

-

-

-

7 1/2

.699

P

56 1/2

17 3/4

15

16 1/2

7 3/4

-

P-1/2

-

-

-

-

8

.716

Q

57 3/4

18

16

17 3/4

8 1/4

-

Q-1/2

-

-

-

-

8 1/2

.732

-

-

18 1/2

17

-

8 5/8

-

R

59

-

-

19

8 7/8

-

R-1/2

-

-

-

-

9

.748

-

-

19

18

-

9 1/8

-

S

60 1/4

-

-

20 1/4

9 3/8

-

S-1/2

-

-

-

-

9 1/2

.764

-

-

19 1/2

19

-

9 5/8

-

T

61 1/2

-

-

21 1/2

10

.781

T-1/2

-

20

20

-

10 1/4

-

U

62 3/4

-

21

22 3/4

10 1/2

.797

U-1/2

-

20 1/4

22

-

10 5/8

-

V

63 3/4

-

-

23 3/4

11

.814

V-1/2

-

20 3/4

23

-

11 1/8

-

W

65

-

-

25

11 3/8

-

W-1/2

-

-

-

-

11 1/2

.830

-

-

21

24

-

11 5/8

-

X

66 1/4

-

-

26 1/4

11 7/8

-

X-1/2

-

-

-

-

12

.846

Y

67 1/2

21 1/4

25

27 1/2

12 1/4

-

Y-1/2

-

-

-

-

12 1/2

.862

Z

68 3/4

21 3/4

26

28 3/4

12 3/4

-

Z-1/2

-

-

-

-

13

.879

-

-

22

27

-