US IT FR UK/AU JP DIAM. (mm) CIRC. (mm)
3 4 44 F 4 14.05 44
4 6.75 47 H 1/2 7 14.86 46.5
5 9.5 50 J 1/2 9 15.7 49.0
6 11.5 52.75 M 12 16.5 51.5
7 14.5 55.25 O 14 17.3 54
8 17 57.75 Q 16 18.2 56.6
 
Because sizing and cut will vary between brands, please use this chart as a general guide. If you are between sizes or need assistance selecting the proper size, please contact Customer Service.