Circumference Diameter Europe UK and Australia United States and Canada SG/JP HK CN Switzerland
(mm) (inches) (mm) (inches)
44.2 1.74 14.1 0.56 44 F1/2 3 4 6 6 4
44.8 1.77 14.3 0.56 45 G 5 51/4
45.5 1.79 14.5 0.57 G1/2 31/2 7.5 7
46.1 1.82 14.7 0.58 46 H 6 61/2
46.8 1.84 14.9 0.59 47 H1/2 4 7 9 8
47.4 1.87 15.1 0.59 I 9 73/4
48.0 1.89 15.3 0.60 48 I1/2 41/2 8 10
48.7 1.92 15.5 0.61 J 9
49.3 1.94 15.7 0.62 49 J1/2 5 9 11 10
50.0 1.97 15.9 0.63 50 K 10
50.6 1.99 16.1 0.63 K1/2 51/2 10 12 11
51.2 2.02 16.3 0.64 51 L 113/4
51.9 2.04 16.5 0.65 52 L1/2 6 11 13 12 123/4
52.5 2.07 16.7 0.66 M 12 13
53.1 2.09 16.9 0.67 53 M1/2 61/2 13 14.5 14
53.8 2.12 17.1 0.67 N 14
54.4 2.14 17.3 0.68 54 N1/2 7 14 16 151/4
55.1 2.17 17.5 0.69 55 O 15
55.7 2.19 17.7 0.70 O1/2 71/2 15 17 161/2
56.3 2.22 17.9 0.71 56 P 16
57.0 2.25 18.1 0.71 57 P1/2 8 16 17 173/4
57.2 2.25 18.2 0.72 18
57.6 2.27 18.3 0.72 Q
58.3 2.30 18.5 0.73 58 Q1/2 81/2 17 19 18
58.9 2.32 18.8 0.74 59 R 19
59.5 2.34 19.0 0.75 R1/2 9 18 20.5 19
60.2 2.37 19.2 0.76 60 S 20 201/4
60.8 2.40 19.4 0.76 61 S1/2 91/2 19 22
61.4 2.42 19.6 0.77 T 21 211/2
62.1 2.45 19.8 0.78 62 T1/2 10 20 23
62.7 2.47 20.0 0.79 U 21 22
63.4 2.50 20.2 0.80 63 U1/2 101/2 22 24 223/4
64.0 2.52 20.4 0.80 64 V 23
64.6 2.55 20.6 0.81 V1/2 11 23 25
65.3 2.57 20.8 0.82 65 W 24 25
65.9 2.60 21.0 0.83 66 W1/2 111/2 24 26 25
66.6 2.62 21.2 0.84 X
67.2 2.65 21.4 0.84 67 X1/2 12 25 27.75 26 271/2
67.8 2.67 21.6 0.85 Y
68.5 2.70 21.8 0.86 68 Z 121/2 26 283/4
69.1 2.72 22.0 0.87 69 Z1/2
69.7 2.75 22.2 0.87 70 13 27 30
70.4 2.77 22.4 0.88 Z+1
71.0 2.80 22.6 0.89 Z+2 131/2