Ring Size Convertor Page

UK EU (mm) Inside Diameter (mm) US Japan
A 38 12.03 0½ -2
A½ 38 12.23 0¾ -2
B 39 12.43 1 -1
B½ 40 12.63 1¼ 0
C 40 12.83 1½ 0
C½ 41 13.03 1¾ 1
D 42 13.23 2 2
D½ 42 13.42 2¼ 2
E 43 13.62 2½ 3
E½ 43 13.82 2¾ 3
F 44 14.02 3 4
F½ 45 14.22 3¼ 5
G 45 14.42 3½ 5
G½ 46 14.62 3¾ 6
H 47 14.82 4 7
H½ 47 15.02 4¼ 7
I 48 15.22 4½ 8
I½ 48 15.41 4¾ 8
J 49 15.61 5 9
J½ 50 15.81 5¼ 10
K 50 16.01 5½ 10
K½ 51 16.21 5¾ 11
L 52 16.41 6 12
L½ 52 16.61 6¼ 12
M 53 16.81 6½ 13
M½ 53 17.01 6¾ 13
N 54 17.20 7 14
N½ 55 17.40 7¼ 15
O 55 17.60 7¼ 15
O½ 56 17.80 7½ 16
P 57 18.00 7¾ 17
P½ 57 18.20 8 17
Q 58 18.40 8¼ 18
Q½ 58 18.60 8½ 18
R 59 18.80 8¾ 19
R½ 60 19.00 9 20
S 60 19.19 9¼ 20
S½ 61 19.39 9½ 21
T 62 19.59 9¾ 22
T½ 62 19.79 10 22
U 63 19.99 10¼ 23
U½ 63 20.19 10½ 23
V 64 20.39 10¾ 24
V½ 65 20.59 11 25
W 65 20.79 11¼ 25
W½ 66 20.98 11½ 26
X 67 21.18 11¾ 27
X½ 67 21.38 12 27
Y 68 21.58 12¼ 28
Y½ 68 21.78 12½ 28
Z 69 21.98 12¾ 29
Z+1 70 22.18 13 30
Z+1½ 70 22.38 13¼ 30
Z+2 71 22.58 13½ 31
Z+2½ 72 22.78 13¾ 32
Z+3 72 22.97 14 32
Z+3½ 73 23.17 14¼ 33
Z+4 73 23.37 14½ 33
Z+4½ 74 23.57 14¾ 34
Z+5 75 23.77 15 35
Z+5½ 75 23.97 15¼ 35
Z+6 76 24.17 15½ 36
Z+6½ 77 24.37 15¾ 37
Z+7 77 24.57 16 37
Z+7½ 78 24.76 16¼ 38
Z+8 78 24.96 16½ 38
Z+8½ 79 25.16 16¾ 39
Z+9 80 25.36 17 40
Z+9½ 80 25.56 17¼ 40
Z+10 81 25.76 17½ 41
Z+10½ 82 25.96 17¾ 42
Z+11 82 26.16 18 42
Z+11½ 83 26.36 18¼ 43
Z+12 83 26.56 18½ 43
Z+12½ 84 26.75 18¾ 44