Ring Size Converter & Chart (US, UK, EU, JP, mm)

US/CA	UK/AU	EU/ISO	JP	Diameter	Circumference
3	—	44	—	14.07 mm	44.2 mm
3.5	—	45.5	—	14.47 mm	45.5 mm
4	H½	46.5	7	14.88 mm	46.7 mm
4.5	I½	48	8	15.29 mm	48 mm
5	J½	49.5	9	15.69 mm	49.3 mm
5.5	K½	50.5	10	16.1 mm	50.6 mm
6	L½	52	12	16.51 mm	51.9 mm
6.5	M½	53	13	16.91 mm	53.1 mm
7	N½	54.5	14	17.32 mm	54.4 mm
7.5	O½	55.5	15	17.73 mm	55.7 mm
8	P½	57	16	18.13 mm	57 mm
8.5	Q½	58	17	18.54 mm	58.2 mm
9	R½	59.5	18	18.95 mm	59.5 mm
9.5	S½	61	19	19.35 mm	60.8 mm
10	T½	62	20	19.76 mm	62.1 mm
10.5	U½	63.5	22	20.16 mm	63.3 mm
11	V½	64.5	23	20.57 mm	64.6 mm
11.5	W½	66	24	20.98 mm	65.9 mm
12	X½	67	25	21.38 mm	67.2 mm
12.5	Z	68.5	26	21.79 mm	68.5 mm
13	Z+1	69.5	27	22.2 mm	69.7 mm

Diameter uses the common US standard: 11.63 mm + 0.8128 mm per size. EU (ISO 8653) size = inner circumference in mm.

FAQ

How do I find my ring size at home?

Wrap a paper strip around the base of the finger, mark it, measure the length in mm (circumference) and look it up in the table.

What size ring is most common?

Women commonly wear US 6–7 and men US 9–10, but always measure.

Sizes vary by brand and seller. Always check the product's own size chart and measure yourself; this chart is a general standard guide.