Question 1

How do I measure my ring size at home?

Accepted Answer

Wrap string or soft tape at the finger base, mark the overlap, and measure in mm. Or measure an existing ring inner diameter. Full steps are in our how to measure ring size at home guide, and you can use the free printable ring sizer.

Question 2

What is US size 7 ring in mm?

Accepted Answer

US size 7 is about 17.32 mm inside diameter and 54.4 mm circumference (UK N½, EU 54.4). See the size 7 row in the chart.

Question 3

What is US size 10 ring in mm?

Accepted Answer

US size 10 is about 19.76 mm inside diameter and 62.1 mm circumference (UK T½, EU ≈62). See the size 10 row in the chart.

Question 4

What is US size 11 ring in mm?

Accepted Answer

US size 11 is about 20.57 mm inside diameter and 64.6 mm circumference (UK V½, EU ≈65). Jump to size 11 in the table.

Question 5

What is 19 mm ring size?

Accepted Answer

19 mm is an inside diameter. On this chart it sits between US 9 (18.95 mm) and US 9¼ (19.15 mm). If 19 mm was a wrap around the finger, that would be a child’s size—double-check whether you measured diameter or circumference.

Question 6

What is 2.5 inches in ring size?

Accepted Answer

2.5 inches as circumference is about 63.5 mm around the finger, closest to US 10½ (63.4 mm, UK U½). 2.5 inches is not a typical inside diameter for a finger ring.

Question 7

What is 6 cm in ring size?

Accepted Answer

Use 6 cm as circumference: 60 mm around the finger, closest to US 9¼ (UK S, EU 60.2). Pick Circumference (cm) in the converter. Adult inside diameters are about 16–22 mm, not 6 cm.

Question 8

What is ring size 52 or 54 (EU)?

Accepted Answer

EU labels track inner circumference in mm. Size 52 is closest to ≈51.9–52.5 mm (about US 6–6¼ / UK L½–M). Size 54 is closest to ≈54.4 mm (about US 7 / UK N½).

Question 9

What is the difference between US and UK ring sizes?

Accepted Answer

US uses numbers with quarter steps (6, 6.5, 7). UK uses letters (L, M, Q). Both map to the same mm diameter and circumference on this chart.

Wrap (cm)	Wrap (mm)	Closest US	UK	EU	Ø mm
5	50	5+1/4	K	50	15.90
5.5	55	7+1/4	O	55.1	17.53
6	60	9+1/4	S	60.2	19.15
6.5	65	11+1/4	W	65.3	20.78
7	70	13	Z½	69.7	22.20

US	UK	EU	Diameter (mm)	Circum. (mm)	Asia	India	Italy/Swiss	Dia. (in)	Circ. (in)
0	-	36.5	11.63	36.5	-	-	-	0.458	1.44
1/4	-	37.2	11.84	37.2	-	-	-	0.466	1.46
1/2	A	37.8	12.04	37.8	-	-	-	0.474	1.49
3/4	A+1/2	38.5	12.24	38.5	-	-	-	0.482	1.51
1	B	39.1	12.45	39.1	1	-	-	0.490	1.54
1+1/4	B+1/2	39.7	12.65	39.7	-	-	-	0.498	1.56
1+1/2	C	40.4	12.85	40.4	-	-	0.4	0.506	1.59
1+3/4	C+1/2	41	13.06	41.0	-	1	1	0.514	1.61
2	D	41.7	13.26	41.7	2	2	1.7	0.522	1.64
2+1/4	D+1/2	42.3	13.46	42.3	-	-	2.3	0.530	1.67
2+1/2	E	42.9	13.67	42.9	3	3	2.9	0.538	1.69
2+3/4	E+1/2	43.6	13.87	43.6	-	4	3.6	0.546	1.72
3	F	44.2	14.07	44.2	4	-	4.2	0.554	1.74
3+1/4	F+1/2	44.8	14.27	44.8	5	5	4.8	0.562	1.77
3+1/2	G	45.5	14.48	45.5	-	-	5.5	0.570	1.79
3+3/4	G+1/2	46.1	14.68	46.1	6	6	6.1	0.578	1.82
4	H	46.8	14.88	46.8	7	-	6.8	0.586	1.84
4+1/4	H+1/2	47.4	15.09	47.4	-	7	7.4	0.594	1.87
4+1/2	I	48	15.29	48.0	8	8	8	0.602	1.89
4+3/4	J	48.7	15.49	48.7	-	9	8.7	0.610	1.92
5	J+1/2	49.3	15.70	49.3	9	-	9.3	0.618	1.94
5+1/4	K	50	15.90	50.0	-	10	10	0.626	1.97
5+1/2	K+1/2	50.6	16.10	50.6	10	-	10.6	0.634	1.99
5+3/4	L	51.2	16.31	51.2	-	11	11.2	0.642	2.02
6	L+1/2	51.9	16.51	51.9	11	12	11.9	0.650	2.04
6+1/4	M	52.5	16.71	52.5	12	-	12.5	0.658	2.07
6+1/2	M+1/2	53.1	16.92	53.1	13	13	13.1	0.666	2.09
6+3/4	N	53.8	17.12	53.8	-	-	13.8	0.674	2.12
7	N+1/2	54.4	17.32	54.4	14	14	14.4	0.682	2.14
7+1/4	O	55.1	17.53	55.1	-	15	15.1	0.690	2.17
7+1/2	O+1/2	55.7	17.73	55.7	15	-	15.7	0.698	2.19
7+3/4	P	56.3	17.93	56.3	-	16	16.3	0.706	2.22
8	P+1/2	57	18.14	57.0	16	17	17	0.714	2.24
8+1/4	P+3/4	57.6	18.34	57.6	-	-	17.6	0.722	2.27
8+1/2	Q+1/4	58.3	18.54	58.3	17	18	18.3	0.730	2.29
8+3/4	R	58.9	18.75	58.9	-	19	18.9	0.738	2.32
9	R+1/2	59.5	18.95	59.5	18	-	19.5	0.746	2.34
9+1/4	S	60.2	19.15	60.2	-	20	20.2	0.754	2.37
9+1/2	S+1/2	60.8	19.35	60.8	19	21	20.8	0.762	2.39
9+3/4	T	61.4	19.56	61.4	-	-	21.4	0.770	2.42
10	T+1/2	62.1	19.76	62.1	20	22	22.1	0.778	2.44
10+1/4	U	62.7	19.96	62.7	21	23	22.7	0.786	2.47
10+1/2	U+1/2	63.4	20.17	63.4	22	-	23.4	0.794	2.49
10+3/4	V	64	20.37	64.0	-	24	24	0.802	2.52
11	V+1/2	64.6	20.57	64.6	23	25	24.6	0.810	2.54
11+1/4	W	65.3	20.78	65.3	-	-	25.3	0.818	2.57
11+1/2	W+1/2	65.9	20.98	65.9	24	26	25.9	0.826	2.59
11+3/4	X	66.6	21.18	66.6	-	-	26.6	0.834	2.62
12	X+1/2	67.2	21.39	67.2	25	27	27.2	0.842	2.65
12+1/4	Y	67.8	21.59	67.8	-	28	27.8	0.850	2.67
12+1/2	Y+1/2	68.5	21.79	68.5	26	-	28.5	0.858	2.70
12+3/4	Z	69.1	22.00	69.1	-	29	29.1	0.866	2.72
13	Z+1/2	69.7	22.20	69.7	27	30	29.7	0.874	2.75
13+1/4	Z1	70.4	22.40	70.4	-	-	30.4	0.882	2.77
13+1/2	-	71	22.61	71.0	-	31	31	0.890	2.80
13+3/4	Z2	71.7	22.81	71.7	-	32	31.7	0.898	2.82
14	Z3	72.3	23.01	72.3	-	-	32.3	0.906	2.85
14+1/4	-	72.9	23.22	72.9	-	33	32.9	0.914	2.87
14+1/2	Z4	73.6	23.42	73.6	-	-	33.6	0.922	2.90
14+3/4	-	74.2	23.62	74.2	-	34	34.2	0.930	2.92
15	-	74.8	23.83	74.8	-	35	34.8	0.938	2.95
15+1/4	-	75.5	24.03	75.5	-	-	35.5	0.946	2.97
15+1/2	-	76.1	24.23	76.1	-	36	36.1	0.954	3.00
15+3/4	-	76.8	24.43	76.8	-	-	36.8	0.962	3.02
16	-	77.4	24.64	77.4	-	37	37.4	0.970	3.05

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

Circumference (mm)

Diameter (mm)

United States

United Kingdom

Europe (EU)

Ring size chart FAQ

Related tools & guides

Measure at home

Printable ring sizer

Ring size converter

Men's ring size chart

Women's ring size chart