Testers & scales calibrated before despatch

Gem & precious metal testers, since 1986

Test Table

UK & IRELAND,

Australia, New Zealand

US

Canada, Mexico

INTERNAL
CIRCUMF.
(mm)

Austria, France, Germany (mostly), Belgium, Norway, Sweden, Finland, Russia (usually), Middle East (usually)

INTERNAL
CIRCUMF.
MINUS 40 
(mm)

Switzerland, Spain, Netherlands, Italy

INTERNAL
DIAMETER
(mm)

Sometimes used in Germany, Argentina, Russia

FAR EAST

Japan, China, Korea, Hong Kong, Taiwan, Singapore

 

0

36.5

-3.5

11.6

 

 

 

37

-3

 

 

 

1/4

37.2

-2.8

11.8

 

A

1/2

37.8

-2.2

12

 

 

 

38

-2

12.1

 

3/4

38.5

-1.5

12.2

 

 

 

39

-1

 

 

B

1

39.1

-0.9

12.4

 

1 1/4

39.7

-0.3

12.6

1

C

 

40

0

12.7

 

1 3/4

41

1

13.1

 

D

2

41.7

1.7

13.3

2

 

 

42

2

13.4

 

2 1/4

42.3

2.3

13.5

 

E

2 1/2

42.9

2.9

13.7

3

 

 

43

3

 

 

2 3/4

43.6

3.6

13.9

 

F

 

44

4

14

 

3

44.2

4.2

14.1

4

G

3 1/4

44.8

4.8

14.3

5

 

 

45

5

 

 

3 1/2

45.5

5.5

14.5

 

H

 

46

6

14.6

6

 

3 3/4

46.1

6.1

14.7

 

4

46.8

6.8

14.9

7

I

 

47

7

15

 

4 1/4

47.4

7.4

15.1

 

J

4 1/2

48

8

15.3

8

4 3/4

48.7

8.7

15.5

 

 

 

49

9

15.6

9

 

5

49.3

9.3

15.7

 

5 1/4

50

10

15.9

10

L

5 1/2

50.6

10.6

16.1

 

 

51

11

16.2

11

 

5 3/4

51.2

11.2

16.3

 

M

6

51.9

11.9

16.5

 

 

 

52

12

16.6

 

6 1/4

52.5

12.5

16.7

12

 

 

53

13

16.9

 

N

6 1/2

53.1

13.1

16.9

13

 

53.5

13.5

17

 

 

6 3/4

53.8

13.8

17.1

 

 

 

54

14

17.2

 

O

7

54.4

14.4

17.3

14

 

55

15

 

 

 

7 1/4

55.1

15.1

17.5

 

P

7 1/2

55.7

15.7

17.7

15

 

 

56

16

17.8

 

7 3/4

56.3

16.3

17.9

 

 

 

56.5

16.5

18

16

Q

8

57

17

18.1

 

8 1/4

57.6

17.6

18.3

17

 

 

58

18

 

 

R

8 1/2

58.3

18.3

18.5

 

 

8 3/4

58.9

18.9

18.7

18

 

59

19

18.8

 

S

9

59.5

19.5

18.9

19

9 1/4

60

20

19.1

 

 

9 1/2

60.8

20.8

19.4

 

T

 

61

21

 

20

9 3/4

61.4

21.4

19.6

 

 

 

62

22

19.7

21

U

10

62.1

22.1

19.8

 

10½

10 1/4

62.7

22.7

20

22

 

 

63

23

20.1

 

V

10 1/2

63.4

23.4

20.2

 

10 3/4

64

24

20.4

23

W

11

64.6

24.6

20.6

24

 

 

65

25

20.7

 

11 1/4

65.3

25.3

20.8

 

X

11 1/2

65.9

25.9

21

25

 

 

66

26

 

 

11 3/4

66.6

26.6

21.2

26

 

 

67

27

21.3

 

Y

12

67.2

27.2

21.4

 

 

12 1/4

67.8

27.8

21.6

 

 

68

28

21.6

27

Z

12 1/2

68.5

28.5

21.8

28

 

 

69

29

 

 

12 3/4

69.1

29.1

22

 

Z+1

13

69.7

29.7

22.2

 

 

 

70

30

22.3

29

Z+1 ½

13 1/4

70.4

30.4

22.4

 

Z+2

13 1/2

71

31

22.6

30

Z+2 ½

13 3/4

71.7

31.7

22.8

 

 

 

72

32

22.9

31

Z+3

14

72.3

32.3

23

 

Z+3 ½

14 1/4

72.9

32.9

23.2

32

 

 

73

33

 

 

Z+4

14 1/2

73.6

33.6

23.4

 

Z+4 ½

 

74

34

 

33

 

14 3/4

74.2

34.2

23.6

 

Z+5

15

74.8

34.8

23.8

 

Z+5 ½

 

75

35

23.9

34

 

15 1/4

75.5

35.5

24

 

 

 

76

36

 

 

Z+6

15 1/2

76.1

36.1

24.2

 

Z+6 ½

15 3/4

76.8

36.8

24.4

 

 

 

77

37

24.5

 

Z+7

16

77.4

37.4

24.6

 


Source for this chart for European sizes https://www.buchkosky.com/education/european_ring_size/

Source for this chart for other sizes International Ring Size Conversion Chart for Comfort Fit – Hanover Jewelers

 

Other sources:

The Official International Ring Size Conversion Chart (ringsizes.co)

International Ring Size Conversion Chart (gessweincanada.com)