RING SIZE CONVERSIONS

Ring Size (USA)	UK Size	Inside Diameter (mm)	Inside Circumference (mm)
1/2	A	11.95	37.54
3/4	A½	12.18	38.26
1	B	12.37	38.86
1 1/4	B½	12.6	39.58
1 1/2	C	12.78	40.15
1 3/4	C½	13	40.84
2	D	13.21	41.5
2 1/4	D½	13.41	42.13
2 1/2	E	13.61	42.76
2 3/4	E½	13.83	43.45
3	F	14.05	44.14
3 1/8	F¼	14.15	44.45
3 1/4	F½	14.25	44.77
3 3/8	F¾	14.36	45.11
3 1/2	G	14.45	45.4
3 5/8	G¼	14.56	45.74
3 3/4	G½	14.65	46.02
4	H	14.86	46.68
4 1/4	H½	15.04	47.25
4 1/2	I	15.27	47.97
4 5/8	I¼	15.4	48.38
4 3/4	I½	15.53	48.79
5	J	15.7	49.32
5 1/8	J¼	15.8	49.64
5 1/4	J½	15.9	49.95
5 3/8	J¾	16	50.27
5 1/2	K	16.1	50.58
5 3/4	K½	16.3	51.21
5 7/8	K¾	16.41	51.55
6	L	16.51	51.87
6 1/4	L½	16.71	52.5
6 1/2	M	16.92	53.16
6 3/4	M½	17.13	53.82
7	N	17.35	54.51
7 1/4	N½	17.45	54.82
7 1/2	O	17.75	55.76
7 3/4	O½	17.97	56.45
8	P	18.19	57.15
8 1/4	P½	18.35	57.65
8 1/2	Q	18.53	58.21
8 5/8	Q¼	18.61	58.47
8 3/4	Q½	18.69	58.72
8 7/8	Q¾	18.8	59.06
9	R	18.89	59.34
9 1/8	R¼	19.1	60
9 1/4	R½	19.22	60.38
9 3/8	R¾	19.31	60.66
9 1/2	S	19.41	60.98
9 5/8	S¼	19.51	61.29
9 3/4	S½	19.62	61.64
10	T	19.84	62.33
10 1/4	T½	20.02	62.89
10 1/2	U	20.2	63.46
10 5/8	U¼	20.32	63.84
10 3/4	U½	20.44	64.21
11	V	20.68	64.97
11 1/8	V¼	20.76	65.22
11 1/4	V½	20.85	65.5
11 3/8	V¾	20.94	65.78
11 1/2	W	21.08	66.22
11 5/8	W¼	21.18	66.54
11 3/4	W½	21.24	66.73
11 7/8	W¾	21.3	66.92
12	X	21.49	67.51
12 1/4	X½	21.69	68.14
12 1/2	Y	21.89	68.77
12 3/4	Y½	22.1	69.43
13	Z	22.33	70.15
13 1/4	Z½	22.4	70.37
13 1/2	Z+1	22.6	71
13 3/4	Z+1½	22.81	71.66
14	Z+2	23.01	72.29
14 1/4	Z+2½	23.22	72.95
14 1/2	Z+3	23.42	73.58
14 3/4	Z+3½	23.62	74.2
15	Z+4	23.83	74.86
15 1/4	Z+4½	24.03	75.49
15 1/2	Z+5	24.23	76.12
15 3/4	Z+5½	24.43	76.75
16	Z+6	24.64	77.41
16 1/4	Z+6½	24.84	78.04
16 1/2	Z+7	25.05	78.7
16 3/4	Z+7½	25.25	79.33
17	Z+8	25.45	79.95