US/AU Size UK Size EU Sizes Inches Milimeters
C2 N/A N/A 3 7/8 98
C3 N/A N/A 4 1/8 107
C4 4 19-20 4 1/2 115
C5 5 20-21 4 7/8 123
C6 6 22-23 5 1/8 132
C7 7 23-24 5 1/2 140
C8 8 24-25 5 7/8 149
C9 9 25-26 6 1/8 157
C10 10 27-28 6 1/2 166
C11 11 28-29 6 7/8 174
C12 12 29-30 7 1/8 183
C13 13 30-31 7 1/2 191
J1 1 32-33 7 7/8 200
J2 2 33-34 8 1/8 208