Ring Size Chart

IRL/GB

Diameter mm

Circumference mm

US/CA

EU/ISO

A

12.04

37.82

½

37 ¾

B

12.45

39.11

1

39

C

12.85

40.37

1 ½

40 ½

D

13.26

41.66

2

41 ¾

E

13.67

42.94

2 ½

43

F

14.07

44.2

3

44 ¼

G

14.48

45.49

3 ½

45 ½

H

14.88

46.75

4

46 ¾

I

15.29

48.03

4 ½

48

J

15.49

48.66

4 ¾

48 ¾

K

15.9

49.95

5 ¼

50

L

16.31

51.24

5 ¾

51 ¼

M

16.71

52.49

6 ¼

52 ½

N

17.12

53.78

6 ¾

53 ¾

O

17.53

55.07

7 ¼

55

P

17.93

56.33

7 ¾

56 ¼

Q

18.34

57.62

8 ¼

57 ½

R

18.75

58.9

8 ¾

59

S

19.15

60.16

9 ¼

60 ¼

T

19.56

61.45

9 ¾

61 ½

U

19.96

62.7

10 ¼

62 ¾

V

20.37

63.99

10 ¾

64

W

20.78

65.28

11 ¼

65 ¼

X

21.18

66.54

11 ¾

66 ½

Y

21.59

67.82

12 ¼

67 ¾

Z

21.79

68.45

12 ½

68 ½

Z+1

22.2

69.74

13

69 ¾

Z+2

22.61

71.03

13 ½

71

Z+3

23.01

72.29

14

72 ¼

Z+4

23.42

73.57

14 ½

73 ½

Z+5

23.83

74.86

15

74 ¾

Z+6

24.23

76.12

15 ½

76 ¼

Z+7

24.64

77.41

16

77 ½