Ring Size Conversion Chart

Inside Diameter		Inside Circumference		Sizes
mm	Inches	mm	Inches	UK & Australia	US & Canada	France & Russia	Germany	Japan	Swiss
14.86	0.585	46.68	1.84	H 1/2	4	-	15	7	-
15.04	0.592	47.25	1.86	I	4 1/4	47 3/4	-	-	7 3/4
15.27	0.601	47.97	1.89	I 1/2	4 1/2	-	15 1/4	8	-
15.40	0.606	48.38	1.90	J	4 5/8	49	15 1/2	-	9
15.53	0.611	48.79	1.92	J 1/4	4 3/4	-	-	-	-
15.70	0.618	49.32	1.94	J 1/2	5	-	15 3/4	9	-
15.80	0.622	49.64	1.95	K	5 1/8	50	-	-	10
15.90	0.626	49.95	1.97	K 1/4	5 1/4	-	-	-	-
16.00	0.630	50.27	1.98	K 1/2	5 3/8	-	-	10	-
16.10	0.634	50.58	1.99	L	5 1/2	51 3/4	16	-	11 3/4
16.30	0.642	51.21	2.02	L 1/4	5 3/4	-	-	-	-
16.41	0.646	51.55	2.03	L 1/2	5 7/8	-	-	-	-
16.51	0.650	51.87	2.04	M	6	52 3/4	16 1/2	12	12 3/4
16.71	0.658	52.50	2.07	M 1/2	6 1/4	-	-	-	-
16.92	0.666	53.16	2.09	N	6 1/2	54	17	13	14
17.13	0.674	53.82	2.12	N 1/2	6 3/4	-	-	-	-
17.35	0.683	54.51	2.15	O	7	55 1/4	17 1/4	14	15 1/4
17.45	0.687	54.82	2.16	O 1/2	7 1/4	-	-	-	-
17.75	0.699	55.76	2.20	P	7 1/2	56 1/2	17 3/4	15	16 1/2
17.97	0.707	56.45	2.22	P 1/2	7 3/4	-	-	-	-
18.19	0.716	57.15	2.25	Q	8	57 3/4	18	16	17 3/4
18.35	0.722	57.65	2.27	Q 1/2	8 1/4	-	-	-	-
18.53	0.729	58.21	2.29	Q 3/4	8 1/2	-	18 1/2	17	-
18.61	0.733	58.47	2.30	R	8 5/8	59	-	-	19
18.69	0.736	58.72	2.31	R 1/4	8 3/4	-	-	-	-
18.80	0.740	59.06	2.32	R 1/2	8 7/8	-	-	-	-
18.89	0.748	59.34	2.35	R 3/4	9	-	19	18	-
19.10	0.752	60.00	2.36	S	9 1/8	60 1/4	-	-	20 1/4
19.22	0.757	60.38	2.38	S 1/4	9 1/4	-	-	-	-
19.31	0.760	60.66	2.39	S 1/2	9 3/8	-	-	-	-
19.41	0.764	60.98	2.40	S 3/4	9 1/2	-	19 1/2	19	-
19.51	0.768	61.29	2.41	T	9 5/8	61 1/2	-	-	21 1/2
19.62	0.772	61.64	2.43	T 1/4	9 3/4	-	-	-	-