International ring size comparison chart

Use this chart to manually convert sizes
Inner Circum (mm)	Inches	UK/IE	EU	US	FR	CH	Inner Diam (mm)	JP	DE
41	1.61		41		41	1	13.05
41.25	1.62	D			41 1/4	1 1/4	13.13
41.5	1.63			2	41 1/2	1 1/2	13.21
41.75	1.64				41 3/4	1 3/4	13.29		13 1/4
42	1.65	D 1/2	42		42	2	13.37	2
42.25	1.66			2 1/4	42 1/4	2 1/4	13.45
42.5	1.67	E			42 1/2	2 1/2	13.53		13 1/2
42.75	1.68			2 1/2	42 3/4	2 3/4	13.61
43	1.69		43		43	3	13.69	3
43.25	1.7	E 1/2			43 1/4	3 1/4	13.77		13 3/4
43.5	1.71			2 3/4	43 1/2	3 1/2	13.85
43.75	1.72	F			43 3/4	3 3/4	13.93
44	1.73		44	3	44	4	14.01	4	14
44.25	1.74				44 1/4	4 1/4	14.09
44.5	1.75	F 1/2			44 1/2	4 1/2	14.16
44.75	1.76			3 1/4	44 3/4	4 3/4	14.24		14 1/4
45	1.77	G	45		45	5	14.32	5
45.25	1.78				45 1/4	5 1/4	14.4
45.5	1.79			3 1/2	45 1/2	5 1/2	14.48		14 1/2
45.75	1.8	G 1/2			45 3/4	5 3/4	14.56
46	1.81		46	3 3/4	46	6	14.64	6
46.25	1.82	H			46 1/4	6 1/4	14.72		14 3/4
46.5	1.83				46 1/2	6 1/2	14.8
46.75	1.84			4	46 3/4	6 3/4	14.88
47	1.85	H 1/2	47		47	7	14.96	7	15
47.25	1.86			4 1/4	47 1/4	7 1/4	15.04
47.5	1.87	I			47 1/2	7 1/2	15.12
47.75	1.88				47 3/4	7 3/4	15.2
48	1.89		48	4 1/2	48	8	15.28		15 1/4
48.25	1.9	I 1/2			48 1/4	8 1/4	15.36	8
48.5	1.91				48 1/2	8 1/2	15.44
48.75	1.92	J		4 3/4	48 3/4	8 3/4	15.52		15 1/2
49	1.93		49		49	9	15.6
49.25	1.94			5	49 1/4	9 1/4	15.68	9
49.5	1.95	J 1/2			49 1/2	9 1/2	15.76		15 3/4
49.75	1.96				49 3/4	9 3/4	15.84
50	1.97	K	50	5 1/4	50	10	15.92
50.25	1.98				50 1/4	10 1/4	16	10	16
50.5	1.99			5 1/2	50 1/2	10 1/2	16.07
50.75	2	K 1/2			50 3/4	10 3/4	16.15
51	2.01		51		51	11	16.23		16 1/4
51.25	2.02	L		5 3/4	51 1/4	11 1/4	16.31	11
51.5	2.03				51 1/2	11 1/2	16.39
51.75	2.04			6	51 3/4	11 3/4	16.47		16 1/2
52	2.05	L 1/2	52		52	12	16.55
52.25	2.06				52 1/4	12 1/4	16.63	12
52.5	2.07	M		6 1/4	52 1/2	12 1/2	16.71		16 3/4
52.75	2.08				52 3/4	12 3/4	16.79
53	2.09		53		53	13	16.87
53.25	2.1	M 1/2		6 1/2	53 1/4	13 1/4	16.95
53.5	2.11				53 1/2	13 1/2	17.03	13	17
53.75	2.12	N		6 3/4	53 3/4	13 3/4	17.11
54	2.13		54		54	14	17.19
54.25	2.14				54 1/4	14 1/4	17.27		17 1/4
54.5	2.15	N 1/2		7	54 1/2	14 1/2	17.35	14
54.75	2.16				54 3/4	14 3/4	17.43
55	2.17	O	55	7 1/4	55	15	17.51		17 1/2
55.25	2.18				55 1/4	15 1/4	17.59
55.5	2.19				55 1/2	15 1/2	17.67	15
55.75	2.19	O 1/2		7 1/2	55 3/4	15 3/4	17.75		17 3/4
56	2.2		56		56	16	17.83
56.25	2.21	P			56 1/4	16 1/4	17.9
56.5	2.22			7 3/4	56 1/2	16 1/2	17.98	16	18
56.75	2.23				56 3/4	16 3/4	18.06
57	2.24	P 1/2	57	8	57	17	18.14
57.25	2.25				57 1/4	17 1/4	18.22		18 1/4
57.5	2.26	Q			57 1/2	17 1/2	18.3	17
57.75	2.27			8 1/4	57 3/4	17 3/4	18.38
58	2.28		58		58	18	18.46		18 1/2
58.25	2.29	Q 1/2		8 1/2	58 1/4	18 1/4	18.54
58.5	2.3				58 1/2	18 1/2	18.62
58.75	2.31	R			58 3/4	18 3/4	18.7	18
59	2.32		59	8 3/4	59	19	18.78		18 3/4
59.25	2.33				59 1/4	19 1/4	18.86
59.5	2.34	R 1/2			59 1/2	19 1/2	18.94
59.75	2.35			9	59 3/4	19 3/4	19.02	19	19
60	2.36	S	60		60	20	19.1
60.25	2.37			9 1/4	60 1/4	20 1/4	19.18
60.5	2.38				60 1/2	20 1/2	19.26		19 1/4
60.75	2.39	S 1/2			60 3/4	20 3/4	19.34	20
61	2.4		61	9 1/2	61	21	19.42
61.25	2.41	T			61 1/4	21 1/4	19.5		19 1/2
61.5	2.42			9 3/4	61 1/2	21 1/2	19.58
61.75	2.43				61 3/4	21 3/4	19.66	21
62	2.44	T 1/2	62		62	22	19.74		19 3/4
62.25	2.45			10	62 1/4	22 1/4	19.81
62.5	2.46	U			62 1/2	22 1/2	19.89
62.75	2.47				62 3/4	22 3/4	19.97	22	20
63	2.48		63	10 1/4	63	23	20.05
63.25	2.49	U 1/2			63 1/4	23 1/4	20.13
63.5	2.5			10 1/2	63 1/2	23 1/2	20.21		20 1/4
63.75	2.51	V			63 3/4	23 3/4	20.29
64	2.52		64		64	24	20.37	23
64.25	2.53			10 3/4	64 1/4	24 1/4	20.45
64.5	2.54	V 1/2			64 1/2	24 1/2	20.53		20 1/2
64.75	2.55			11	64 3/4	24 3/4	20.61
65	2.56	W	65		65	25	20.69	24
65.25	2.57				65 1/4	25 1/4	20.77		20 3/4
65.5	2.58			11 1/4	65 1/2	25 1/2	20.85
65.75	2.59	W 1/2			65 3/4	25 3/4	20.93
66	2.6		66	11 1/2	66	26	21.01	25	21
66.25	2.61	X			66 1/4	26 1/4	21.09
66.5	2.62				66 1/2	26 1/2	21.17
66.75	2.63			11 3/4	66 3/4	26 3/4	21.25		21 1/4
67	2.64	X 1/2	67		67	27	21.33	26
67.25	2.65				67 1/4	27 1/4	21.41
67.5	2.66	Y		12	67 1/2	27 1/2	21.49		21 1/2
67.75	2.67				67 3/4	27 3/4	21.57
68	2.68		68	12 1/4	68	28	21.65	27
68.25	2.69	Y 1/2			68 1/4	28 1/4	21.72		21 3/4
68.5	2.7				68 1/2	28 1/2	21.8
68.75	2.71	Z		12 1/2	68 3/4	28 3/4	21.88
69	2.72		69		69	29	21.96	28	22
69.25	2.73			12 3/4	69 1/4	29 1/4	22.04
69.5	2.74	Z 1/2			69 1/2	29 1/2	22.12
69.75	2.75				69 3/4	29 3/4	22.2
70	2.76	Z+1	70	13	70	30	22.28		22 1/4
70.25	2.77				70 1/4	30 1/4	22.36	29
70.5	2.78				70 1/2	30 1/2	22.44
70.75	2.79	Z+1 1/2		13 1/4	70 3/4	30 3/4	22.52		22 1/2
71	2.8		71		71	31	22.6
71.25	2.81	Z+2			71 1/4	31 1/4	22.68	30
71.5	2.81			13 1/2	71 1/2	31 1/2	22.76		22 3/4
71.75	2.82				71 3/4	31 3/4	22.84
72	2.83	Z+2 1/2	72	13 3/4	72	32	22.92
72.25	2.84				72 1/4	32 1/4	23	31	23
72.5	2.85	Z+3		14	72 1/2	32 1/2	23.08
72.75	2.86				72 3/4	32 3/4	23.16
73	2.87		73		73	33	23.24		23 1/4
73.25	2.88	Z+3 1/2		14 1/4	73 1/4	33 1/4	23.32	32
73.5	2.89				73 1/2	33 1/2	23.4
73.75	2.9	Z+4			73 3/4	33 3/4	23.48		23 1/2
74	2.91		74	14 1/2	74	34	23.55
74.25	2.92				74 1/4	34 1/4	23.63	33
74.5	2.93	Z+4 1/2		14 3/4	74 1/2	34 1/2	23.71
74.75	2.94				74 3/4	34 3/4	23.79		23 3/4
75	2.95	Z+5	75		75	35	23.87
75.25	2.96			15	75 1/4	35 1/4	23.95
75.5	2.97				75 1/2	35.5	24.03	34	24
75.75	2.98	Z+5 ½		15 1/4	75 3/4	35 3/4	24.11
76	2.99		76		76	36	24.19
76.25	3	Z+6			76 1/4	36 1/4	24.27		24 1/4
76.5	3.01			15 1/2	76 1/2	36.5	24.35	35
76.75	3.02				76 3/4	36 3/4	24.43
77	3.03	Z+6 ½	77	15 3/4	77	37	24.51		24 1/2
77.25	3.04				77 1/4	37 1/4	24.59
77.5	3.05	Z+7			77 1/2	37.5	24.67	36
77.75	3.06			16	77 3/4	37 3/4	24.75		24 3/4
78	3.07		78		78	38	24.83
78.25	3.08	Z+7 ½			78 1/4	38 1/4	24.91
78.5	3.09			16 1/4	78 1/2	38.5	24.99	37	25
78.75	3.1	Z+8			78 3/4	38 3/4	25.07
79	3.11		79	16 1/2	79	39	25.15
79.25	3.12				79 1/4	39 1/4	25.23		25 1/4
79.5	3.13	Z+8 ½			79 1/2	39.5	25.31	38
79.75	3.14			16 3/4	79 3/4	39 3/4	25.39
80	3.15	Z+9	80		80	40	25.46		25 1/2
80.25	3.16			17	80 1/4	40 1/4	25.54
80.5	3.17				80 1/2	40.5	25.62
80.75	3.18	Z+9 ½			80 3/4	40 3/4	25.7	39
81	3.19		81	17 1/4	81	41	25.78		25 3/4
81.25	3.2	Z+10			81 1/4	41 1/4	25.86