Jewelry Size Guide

Ring Size Converter

Convert ring sizes between US, UK, and EU standards instantly. Our chart includes half sizes from 3 to 13 with precise circumference and diameter measurements in millimeters.

Quick Converter

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US / Canada	UK / Australia	EU	Circumference (mm)	Diameter (mm)
3	F	44	44.2	14.1
3.5	G	45.5	45.5	14.5
4	H	47	46.8	14.9
4.5	I	48	48.0	15.3
5	J	49	49.3	15.7
5.5	K	50.5	50.6	16.1
6	L	51.5	51.9	16.5
6.5	M	53	53.1	16.9
7	N	54	54.4	17.3
7.5	O	55.5	55.7	17.7
8	P	57	57.0	18.1
8.5	Q	58	58.3	18.5
9	R	59	59.5	18.9
9.5	S	60.5	60.8	19.4
10	T	62	62.1	19.8
10.5	U	63	63.4	20.2
11	V	64	64.6	20.6
11.5	W	65.5	65.9	21.0
12	X	67	67.2	21.4
12.5	Y	68	68.5	21.8
13	Z	69	69.7	22.2

Click any row to highlight it. Sizes are approximate and may vary by brand.

Understanding Ring Sizing Standards

US / Canadian

The US and Canadian system uses numerical sizes with half-size increments from 0 to 16. Each full size represents a 2.55 mm increase in circumference. This is the most widely used system internationally and is the standard reference point for most online jewelry retailers.

UK / Australian

The UK and Australian system uses alphabetical letters from A to Z, with half sizes expressed using fractions. The scale begins at size A (37.8 mm circumference) and progresses through the alphabet. This system is also used in South Africa, Ireland, and New Zealand.

European

European ring sizes correspond directly to the inner circumference of the ring in millimeters, making them the most intuitive system. A size 52 ring has an internal circumference of approximately 52 mm. This system is used throughout continental Europe, Scandinavia, and much of South America.

How to Measure Your Ring Size at Home

String Method

Wrap a thin piece of string or paper strip snugly around the base of your finger. Mark where the ends overlap, then lay it flat and measure the length in millimeters. Match this circumference to the chart above.

Existing Ring Method

Place a ring that fits well on a ruler and measure the inside diameter in millimeters. Compare the diameter to the chart. This is the most accurate home method if you already own a well-fitting ring.

Printable Sizer

Many jewelers offer printable ring sizers you can download. Cut out the strip, wrap it around your finger, and read your size directly. Always verify your printer is set to 100% scale with no page fitting enabled.

Pro tip: Measure your finger at the end of the day when it is slightly swollen. Avoid measuring when your hands are cold, as fingers shrink in cooler temperatures and the ring may end up too loose.

Frequently Asked Questions

What is the most common ring size for women?

The most common ring size for women in the US is between 6 and 7 (UK L to N, EU 51.5 to 54). However, ring size varies greatly by individual. Always measure rather than guess, especially for engagement or wedding rings.

What is the most common ring size for men?

Most men wear between a US size 9 and 11 (UK R to V, EU 59 to 64). Men's ring fingers tend to be wider and thicker, so comfort-fit bands with slightly rounded interiors are popular for everyday wear.

Does ring size change with temperature or time of day?

Yes. Fingers swell in heat, humidity, and after physical activity, and shrink in cold weather. They also tend to be slightly larger in the evening than in the morning. For the most accurate reading, measure at room temperature in the late afternoon.

What if my size falls between two sizes on the chart?

If your measurement falls between two sizes, round up to the next half size. A slightly loose ring is more comfortable than a tight one, and most jewelers can add sizing beads or use ring adjusters for minor tweaks.