Free worldwide shipping for orders over $300. Use code FREESHIP

RING SIZE CONVERSION GUIDE

A nifty little guide to determine your ring size based on information  compiled from many sources in various countries to help you determine your ring size.

At Lustre, our rings are available in size from between a U.S. ring size 5 to a U.S. ring size 8. Do email us if you have any questions.

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

-

0

-

-

-

-

10.72

0.442

33.68

1.39

-

0

-

-

-

-

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

-

-

-

-

-