Ring Size

Italian Size	UK Size	French Size	US Size	Inside C. mm.	Diameter mm.
9	J	49		4.90	1.56
9.50	J-1/2	49.25	5	4.96	1.58
10	K	50		5.02	1.60
10.50	L	50.50	5.5	5.06	1.61
11	L-1/2	51		5.09	1.62
11.50	M	51.50	6	5.12	1.63
12		52		5.18	1.65
12.50		52.50		5.21	1.66
13	N	53	6.5	5.28	1.68
13.50	N	53.50		5.34	1.70
14		54		5.40	1.72
14.50	O	54.50	7	5.43	1.73
15		55		5.46	1.74
15.50		55.50		5.53	1.76
16	P	56	7.5	5.59	1.78
16.50	P-1/2	56.50		5.65	1.80
17	Q	57	8	5.68	1.81
17.50		57.50		5.75	1.83
18		58		5.81	1.85
18.50		58.50	8.5	5.84	1.86
19	R	59		5.90	1.88
19.50	R-1/2	59.75	9	5.97	1.90
20	S	60		6.03	1.92