US Size	Inside Diameter (mm)	Inside Circumference (mm)	UK & South Africa Equivalent
5	15.7	49.3	J ½
6	16.5	51.8	L ½
7	17.3	54.4	N ½
8	18.1	56.9	P ½
9	18.9	59.5	R ½
10	19.8	62.1	T ½

 

Please note: The width of a ring must be taken into account when placing an order, as wider style rings will be a tighter fit than a thinner band in the same size.