International Ring Size Chart

Complete ring size conversion chart with US, UK, EU, Asian, Indian, and Italian/Swiss standards. Find your perfect ring size with accurate diameter and circumference measurements.

How to Measure Your Ring Size

Method 1: Using String or Tape

1. Wrap a string or soft measuring tape around your finger
2. Mark where the string overlaps
3. Measure the length with a ruler
4. Use the circumference measurement to find your size
5. For diameter, divide circumference by 3.14 (π)

Method 2: Using Existing Ring

1. Take a ring that fits the intended finger
2. Measure the inner diameter with a ruler
3. Compare with the diameter measurements in the chart
4. Consider that fingers swell during the day
5. Measure when your hands are at room temperature

💡 Tip: Fingers are typically larger in the evening and smaller in the morning. Measure when your hands are at normal temperature for the most accurate size.

Complete Ring Size Conversion Chart

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

Ring Size Standards by Region

🇺🇸 United States

Uses a numerical scale with quarter steps. Sizes range from 0 to 16, with each whole size differing by 0.032 inches in internal diameter.

🇬🇧 United Kingdom

Uses an alphabetical scale (A-Z) with half sizes. Each alphabetical size division equals 1.25mm of circumferential length.

🇪🇺 Europe (ISO)

Based on inner circumference in millimeters. The EU size number directly represents the circumference measurement in mm.

🌏 East Asia

Uses a numerical scale with whole sizes. Common in China, Japan, and South Korea. No linear correlation with diameter or circumference.

🇮🇳 India

Uses a numerical scale with whole sizes. Sizes typically range from 1 to 37, with no linear correlation to measurements.

🇮🇹 Italy/Switzerland

Uses the Swiss Ring Size System, specified as circumference minus 40mm. Also known as the Continental European system.

📏 ISO Standard

Based on inner circumference in millimeters. Used in Austria, France, Belgium, and other Continental European countries.

Frequently Asked Questions

How do I measure my ring size?

You can measure your ring size using a soft measuring tape or string. Wrap it around your finger at the base where the ring will sit, mark the overlap point, and measure the length. For circumference, use the measured length directly. For diameter, divide the circumference by 3.14 (π).

What is the difference between US and UK ring sizes?

US ring sizes use a numerical scale with quarter steps (like 6, 6.25, 6.5), while UK ring sizes use an alphabetical scale (like F, G, H). The UK system is based on the inner circumference in millimeters, with each letter representing a 1.25mm difference.

Are ring sizes the same worldwide?

No, ring sizes vary by region. Different countries use different measurement systems and standards. For example, US sizes are numerical, UK sizes are alphabetical, EU sizes are based on circumference in millimeters, and Asian sizes often use different numerical ranges.

How accurate are ring size conversions?

Ring size conversions are generally accurate when using standardized measurements. However, slight variations may exist between brands due to different manufacturing standards. It's always best to try on rings when possible or consult with a jeweler for the most accurate fit.