The useful details

Ring Size Conversion Chart

Find your fit

A little conversion. A lot more confidence.

Start with the size you already know. We’ll match it across UK and US sizing, then show the measurements behind the fit.

Start with the size you know

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Enter your UK ring size

Letters and quarter sizes are welcome.

Closest match

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All sixty sizes Browse every conversion

UK and US ring size conversions with diameter and circumference in millimetres
UK size	US size	Diameter (mm)	Circumference (mm)
D	2	13.21	41.5
D 1/2	2.25	13.41	42.13
E	2.5	13.61	42.76
E 1/2	2.75	13.83	43.45
F	2.875	14.05	44.14
F 1/2	3	14.15	44.45
F 3/4	3.125	14.25	44.77
G	3.25	14.36	45.11
G 1/4	3.375	14.45	45.4
G 1/2	3.5	14.56	45.74
H	3.75	14.65	46.02
H 1/2	4	14.86	46.68
I	4.25	15.04	47.25
I 1/2	4.5	15.27	47.97
J	4.75	15.4	48.38
J 1/4	4.875	15.53	48.79
J 1/2	5	15.7	49.32
K	5.25	15.8	49.64
K 1/4	5.375	15.9	49.95
K 1/2	5.5	16	50.27
L	5.75	16.1	50.58
L 1/4	5.875	16.3	51.21
L 1/2	6	16.41	51.55
M	6.25	16.51	51.87
M 1/2	6.5	16.71	52.5
N	6.75	16.92	53.16
N 1/2	7	17.13	53.82
O	7.25	17.35	54.51
O 1/2	7.5	17.45	54.82
P	7.75	17.75	55.76
P 1/2	8	17.97	56.45
Q	8.25	18.19	57.15
Q 1/2	8.5	18.35	57.65
Q 3/4	8.625	18.53	58.21
R	8.75	18.61	58.47
R 1/4	8.875	18.69	58.72
R 1/2	9	18.8	59.06
R 3/4	9.125	18.89	59.34
S	9.25	19.1	60
S 1/4	9.375	19.22	60.38
S 1/2	9.5	19.31	60.66
S 3/4	9.625	19.41	60.98
T	9.75	19.51	61.29
T 1/4	9.875	19.62	61.64
T 1/2	10	19.84	62.33
U	10.25	20.02	62.89
U 1/2	10.5	20.2	63.46
V	10.625	20.32	63.84
V 1/4	10.75	20.44	64.21
V 1/2	11	20.68	64.97
W	11.125	20.76	65.22
W 1/4	11.25	20.85	65.5
W 1/2	11.375	20.94	65.78
W 3/4	11.5	21.08	66.22
X	11.625	21.18	66.54
X 1/4	11.75	21.24	66.73
X 1/2	12	21.3	66.92
Y	12.25	21.49	67.51
Y 1/2	12.375	21.69	68.14
Z	12.5	21.89	68.77