UK | USA | French / German | Italian | Circumference (mm) | Diameter (mm) |
A | 39 | 37.7 | 12 | ||
A 1/2 | 39.5 | 38.33 | 12.2 | ||
B | 40 | 38.96 | 12.4 | ||
B 1/2 | 0.75 | 40.8 | 39.58 | 12.6 | |
C | 1.25 | 41.25 | 40.53 | 12.9 | |
C 1/2 | 1.5 | 41 | 1 | 41.15 | 13.1 |
D | 1.75 | 42 | 2 | 41.78 | 13.3 |
D 1/2 | 2 | 42.5 | 2.5 | 42.41 | 13.5 |
E | 2.25 | 43.5 | 3.5 | 43.04 | 13.7 |
E 1/2 | 2.5 | 44 | 4 | 43.67 | 13.9 |
F | 2.75 | 44.5 | 4.5 | 44.3 | 14.1 |
F 1/2 | 3 | 45 | 5 | 44.92 | 14.3 |
G | 3.25 | 45.5 | 5.5 | 45.55 | 14.5 |
G 1/2 | 3.5 | 46 | 6 | 46.18 | 14.7 |
H | 3.75 | 47 | 7 | 46.81 | 14.9 |
H 1/2 | 4 | 47.5 | 7.5 | 47.44 | 15.1 |
I | 4.25 | 48 | 8 | 48.07 | 15.3 |
I 1/2 | 4.5 | 48.5 | 8.5 | 48.69 | 15.5 |
J | 4.75 | 49.5 | 9.5 | 49.32 | 15.7 |
J 1/2 | 5 | 50 | 10 | 49.95 | 15.9 |
K | 5.25 | 50.5 | 10.5 | 50.58 | 16.1 |
K 1/2 | 5.5 | 51 | 11 | 51.21 | 16.3 |
L | 5.75 | 52 | 12 | 51.84 | 16.5 |
L 1/2 | 6 | 52.5 | 12.5 | 52.46 | 16.7 |
M | 6.25 | 53 | 13 | 53.09 | 16.9 |
M 1/2 | 6.5 | 54 | 14 | 53.72 | 17.1 |
N | 6.75 | 54.5 | 14.5 | 54.35 | 17.3 |
N 1/2 | 7 | 55 | 15 | 54.98 | 17.5 |
O | 7.25 | 55.75 | 15.75 | 55.61 | 17.7 |
O 1/2 | 7.5 | 56.25 | 16.25 | 56.23 | 17.9 |
P | 7.75 | 57 | 17 | 56.86 | 18.1 |
P 1/2 | 8 | 57.25 | 17.25 | 57.49 | 18.3 |
Q | 8.25 | 58 | 18 | 58.12 | 18.5 |
Q 1/2 | 8.5 | 58.5 | 18.5 | 58.75 | 18.7 |
R | 8.75 | 59.5 | 19.5 | 59.38 | 18.9 |
R 1/2 | 9 | 60 | 20 | 60 | 19.1 |
S | 9.25 | 60.5 | 20.5 | 60.63 | 19.3 |
S 1/2 | 9.5 | 61.25 | 21.25 | 61.26 | 19.5 |
T | 9.75 | 62 | 22 | 61.89 | 19.7 |
T 1/2 | 10 | 62.5 | 22.5 | 62.52 | 19.9 |
U | 10.5 | 63 | 23 | 63.15 | 20.1 |
U 1/2 | 10.5 | 64 | 24 | 63.77 | 20.3 |
V | 10.75 | 64.25 | 24.25 | 64.4 | 20.5 |
V 1/2 | 11 | 65 | 25 | 65.03 | 20.7 |
W | 11.25 | 65.5 | 25.5 | 65.66 | 20.9 |
W 1/2 | 11.5 | 66.5 | 26.5 | 66.29 | 21.1 |
X | 11.75 | 67 | 27 | 66.92 | 21.3 |
X 1/2 | 12 | 67.5 | 27.5 | 67.54 | 21.5 |
Y | 12.25 | 68 | 28 | 68.17 | 21.7 |
Y 1/2 | 12.5 | 69 | 29 | 68.8 | 21.9 |
Z | 12.75 | 69.5 | 29.5 | 69.43 | 22.1 |
Z 1/2 | 13 | 70 | 30 | 70.06 | 22.3 |
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