Sizing Tips

Ring Size Chart for US Rings

Our size chart is ideal for anyone purchasing a ring in US sizes, as it provides the converted sizes in all major international systems. With our chart, you can easily find the corresponding EU, IT, UK, East Asian and circumference measurements for each US ring size:

US	Circum.	Diam.	ISO / EU	UK	IT	East Asia
0	36.5mm (1.44")	11.6mm	40	A	0	1
0 ¼	37.1mm (1.46")	11.8mm	40	A	0	1
0 ½	37.8mm (1.49")	12.0mm	40	A	0	1
0 ¾	38.4mm (1.51")	12.2mm	40	A 1/2	0	1
1	39.0mm (1.54")	12.4mm	40	B	0	1
1 ¼	39.7mm (1.56")	12.6mm	40	C	0	1
1 ½	40.3mm (1.59")	12.8mm	40	C 1/2	0	1
1 ¾	41.0mm (1.61")	13.0mm	41	D	1	1
2	41.6mm (1.64")	13.2mm	42	D 1/2	2	2
2 ¼	42.2mm (1.66")	13.4mm	42	E	2	2
2 ½	42.9mm (1.69")	13.6mm	43	E 1/2	3	3
2 ¾	43.5mm (1.71")	13.8mm	44	F	4	4
3	44.1mm (1.74")	14.1mm	44	F 1/2	4	4
3 ¼	44.8mm (1.76")	14.3mm	45	G	5	5
3 ½	45.4mm (1.79")	14.5mm	45	G 1/2	5	5
3 ¾	46.1mm (1.81")	14.7mm	46	H	6	6
4	46.7mm (1.84")	14.9mm	47	H 1/2	7	7
4 ¼	47.3mm (1.86")	15.1mm	47	I	7	7
4 ½	48.0mm (1.89")	15.3mm	48	I 1/2	8	8
4 ¾	48.6mm (1.91")	15.5mm	49	J	9	8
5	49.3mm (1.94")	15.7mm	49	J 1/2	9	9
5 ¼	49.9mm (1.96")	15.9mm	50	K	10	10
5 ½	50.5mm (1.99")	16.1mm	51	K 1/2	11	10
5 ¾	51.2mm (2.01")	16.3mm	51	L	11	11
6	51.8mm (2.04")	16.5mm	52	L 1/2	12	11
6 ¼	52.4mm (2.06")	16.7mm	52	M	12	12
6 ½	53.1mm (2.09")	16.9mm	53	M 1/2	13	13
6 ¾	53.7mm (2.11")	17.1mm	54	N	14	13
7	54.4mm (2.14")	17.3mm	54	N 1/2	14	14
7 ¼	55.0mm (2.16")	17.5mm	55	O	15	15
7 ½	55.6mm (2.19")	17.7mm	56	O 1/2	16	15
7 ¾	56.3mm (2.21")	17.9mm	56	P	16	16
8	56.9mm (2.24")	18.1mm	57	P 1/2	17	16
8 ¼	57.5mm (2.27")	18.3mm	58	Q	18	17
8 ½	58.2mm (2.29")	18.5mm	58	Q 1/2	18	18
8 ¾	58.8mm (2.32")	18.7mm	59	R	19	18
9	59.5mm (2.34")	18.9mm	59	R 1/2	19	19
9 ¼	60.1mm (2.37")	19.1mm	60	S	20	19
9 ½	60.7mm (2.39")	19.3mm	61	S 1/2	21	20
9 ¾	61.4mm (2.42")	19.5mm	61	T	21	21
10	62.0mm (2.44")	19.7mm	62	T 1/2	22	21
10 ¼	62.6mm (2.47")	19.9mm	63	U	23	22
10 ½	63.3mm (2.49")	20.1mm	63	U 1/2	23	22
10 ¾	63.9mm (2.52")	20.3mm	64	V	24	23
11	64.5mm (2.54")	20.5mm	65	V 1/2	25	24
11 ¼	65.2mm (2.57")	20.8mm	65	W	25	24
11 ½	65.8mm (2.59")	21.0mm	66	W 1/2	26	25
11 ¾	66.5mm (2.62")	21.2mm	66	X	26	25
12	67.1mm (2.64")	21.4mm	67	X 1/2	27	26
12 ¼	67.7mm (2.67")	21.6mm	68	Y	28	27
12 ½	68.4mm (2.69")	21.8mm	68	Y 1/2	28	27
12 ¾	69.0mm (2.72")	22.0mm	69	Z	29	28
13	69.7mm (2.74")	22.2mm	70	Z1	30	29
13 ¼	70.3mm (2.77")	22.4mm	70	Z1	30	29
13 ½	70.9mm (2.79")	22.6mm	71	Z1 1/2	31	30
13 ¾	71.6mm (2.82")	22.8mm	72	Z2	32	30
14	72.2mm (2.84")	23.0mm	72	Z3	32	31
14 ¼	72.8mm (2.87")	23.2mm	73	Z3 1/2	33	32
14 ½	73.5mm (2.89")	23.4mm	73	Z4	33	32
14 ¾	74.1mm (2.92")	23.6mm	74	Z4	34	33
15	74.8mm (2.94")	23.8mm	75	Z4	35	33

When shopping for rings online, understanding international ring size charts is essential. Different countries use different measurement systems, making it important to convert sizes accurately. Here’s a guide to the most common systems: EU (ISO, millimeter), Circumference, US, IT, East Asian and UK ring sizes.

US Ring Sizes

The United States, Canada and Mexico use a numerical scale, typically ranging from size 3 (about 44 mm circumference) to size 13 (about 70 mm circumference). US sizes increase by 0.25 increments.

EU (ISO) / Millimeter Sizes

The European (EU) ring size system, also called ISO, is based on the inner circumference of the ring in millimeters. For example, an EU size 54 means the inside circumference of the ring is 54 mm.

Circumference

Circumference simply refers to the measurement around the inside of the ring in millimeters. This is often the same number as the EU size, making it easy to match.

IT Ring Sizes

Italy, Spain, Netherlands and Switzerland use a system similar to EU sizes, but often offset by a certain number, usually minus 40. So, an Italian size 14 would correspond to an EU size 54.

UK Ring Sizes

The United Kingdom, Ireland, Australia, South Africa and New Zealand use an alphabetical system, with sizes ranging from A (smallest) to Z+ (largest). For example, a UK size N is roughly equivalent to a US size 7 or EU size 54.

East Asian and South American Ring Sizes

Several East and Southeast Asian countries including Japan, China, South Korea, Hong Kong, Taiwan, Singapore, and even parts of South America, use a diameter-based numerical ring sizing system, often dubbed the “Japanese” or “Asian” system. Unlike Western systems that rely on circumference or alphabetic scales, this system starts at size 1 (13 mm internal diameter) and increases in fixed 0.33 mm increments per size (e.g., size 2 is 13.33 mm, size 3 is 13.67 mm, and so on). This diameter-based metric ensures straightforward conversion: each ring’s internal diameter directly corresponds to an integer Asian size.

Why Use a Ring Size Chart?

A ring size conversion chart makes international shopping much easier and prevents costly mistakes. Always measure your finger in millimeters for the most accurate fit and use a reputable international ring size chart for conversions. This ensures you get the perfect fit, no matter where you shop!