International Ring Size Chart

The most complete ring size reference table online — US, UK, EU, Indian, Japanese, and exact millimeter measurements side by side.

US	UK	EU	India	Japan	Ø mm	C mm
3	F	44	3	4	14.05	44.2
3.5	G	45.5	4	5	14.45	45.4
4	H	46.8	5	7	14.86	46.7
4.5	I	48	6	8	15.27	47.9
5	J½	49.3	8	9	15.7	49.3	👩 Women's common
5.5	K½	50.6	9	10	16.1	50.6	👩 Women's common
6	L½	51.9	10	12	16.51	51.9	👩 Women's common
6.5	M½	53.1	11	13	16.92	53.1	👩 Women's common
7	N½	54.4	13	14	17.35	54.5	👩 Women's common
7.5	O½	55.7	14	15	17.75	55.8
8	P½	57	15	16	18.19	57.2
8.5	Q½	58.3	17	17	18.53	58.2
9	R½	59.5	18	18	18.89	59.3	👨 Men's common
9.5	S½	60.8	19	19	19.41	61	👨 Men's common
10	T½	62.1	20	20	19.84	62.3	👨 Men's common
10.5	U½	63.4	21	21	20.2	63.5	👨 Men's common
11	V½	64.6	22	22	20.68	64.9	👨 Men's common
11.5	W½	65.9	23	23	21.08	66.2
12	X½	67.2	25	25	21.49	67.5
12.5	Z	68.5	26	26	21.89	68.8
13	Z+1	69.7	27	27	22.33	70.1

How to Read This Chart

Each row in the chart represents one physical ring size. The US column uses a numerical system (3–13 with half sizes), while the UK uses an alphabetical system (F through Z+). The EU column reflects the inner circumference in millimeters, which is why those numbers are larger.

The Indian and Japanese systems both use numbered scales, but they are not interchangeable — an Indian size 10 is not the same as a Japanese size 10. Always specify which system you're using when sharing your ring size internationally.

If you're ordering a wide band ring (wider than 6mm), consider going up by half a size from your measured result. Wide bands sit tighter on the finger. Our ring size calculator includes a wide band adjustment toggle, and you can read more in our wide band guide.

How Each System Works

US System

The US system uses numbers from 3 to 13 with half-size increments. It's the most widely used system in North America and is based on the inner diameter of the ring measured in 64ths of an inch increments.

UK System

The UK system uses alphabetical letters from A to Z, with half sizes denoted by ½ (e.g., J½, N½). It's used across the UK, Australia, New Zealand, and South Africa. After Z, sizes continue as Z+1, Z+2, etc.

EU System

European ring sizes directly represent the inner circumference of the ring in millimeters. A size 52 ring has an inner circumference of approximately 52mm. This makes it the most intuitive system for precise measurements.

Indian System

India uses a numbered scale from 1 to 30. It's similar but not identical to the Japanese system. Ring sizes in India are commonly used for both traditional and contemporary jewelry. Use our converter to translate between Indian and other international sizes.

Japanese System

Japan uses a numbered scale (1–30) that differs from the Indian system despite both being numerical. Japanese sizes are based on the Japanese Industrial Standard (JIS). A Japanese size 9 corresponds to roughly a US 5.