Conversion table

Circumference in mm Diameter in mm England USA / Canada France Japan
40 12.7 C. 1.4 (1) 0.0 0.2
41 13.0 C 1/2 1.8 (1-) 1.0 1.1
42 13.4 D 1/2 2.2 (2) 2.0 2.1
43 13.7 E 1/2 2.6 (2-) 3.0 3.1
44 14.0 F. 3.0 (2-) 4.0 4.0
45 14.3 G 3.4 (3) 5.0 5.0
46 14.6 G 1/2 3.7 (3-) 6.0 5.9
47 15.0 H 1/2 4.1 (4) 7.0 6.9
48 15.3 I 1/2 4.5 (4-) 8.0 7.8
49 15.6 J 4.9 (4-) 9.0 8.8
50 15.9 K 5.3 (5) 10.0 9.7
51 16.2 K 1/2 5.7 (5-) 11.0 10.7
52 16.6 L 1/2 6.1 (6) 12.0 11.6
53 16.9 M 1/2 6.4 (6) 13.0 12.6
54 17.2 N 6.8 (6-) 14.0 13.6
55 17.5 O 7.2 (7) 15.0 14.5
56 17.8 P 7.6 (7-) 16.0 15.5
57 18.1 P 1/2 8.0 (7-) 17.0 16.4
58 18.5 Q 1/2 8.4 (8) 18.0 17.4
59 18.8 R. 8.7 (8-) 19.0 18.3
60 19.1 S. 9.1 (9) 20.0 19.3
61 19.4 T 9.5 (9-) 21.0 20.2
62 19.7 T 1/2 9.9 (9-) 22.0 21.2
63 20.1 U 1/2 10.3 (10) 23.0 22.2
64 20.4 V 10.7 (10-) 24.0 23.1
65 20.7 W. 11.0 (11) 25.0 24.1
66 21.0 X 11.4 (11) 26.0 25.0
67 21.3 X 1/2 11.8 (11-) 27.0 26.0
68 21.6 Y 1/2 12.2 (12) 28.0 26.9
69 22.0 Z 1/2 12.6 (12-) 29.0 27.9
70 22.3 Z +1 13.0 (12-) 30.0 28.8