Everything You Need To Know About Ring Sizes

If you’ve ever been stumped by ring size and circumference, you’ve come to the right place. After all, understanding ring sizes isn’t just about getting the fit right. It’s about providing a seamless customer experience, boosting your reputation, and essentially, increasing your sales. 

We’ll be discussing everything from ring size definition, diameter, and circumference to understanding ring sizes across different countries.

So, let’s dive in, shall we?

Understanding Ring Size, Diameter, and Circumference

When it comes to rings, size does matter. 

But what exactly is ring size? Ring size refers to the internal diameter and circumference of a ring. 

The diameter is the straight line passing from side to side through the center of the ring. On the other hand, the circumference is the distance around the ring.

Why is this so crucial? Because knowing the exact size of your ring ensures a comfortable and secure fit. No one wants a ring that’s too tight or too loose, right? 

Ring Sizes Across Different Countries

Now here’s where things get a bit tricky. Did you know that ring sizes vary from country to country? That’s right! A size 7 in the US isn’t the same as a size 7 in the UK, France, or Japan. 

This is because different countries have different methods of ring size measurement. In the US and Canada, ring sizes are determined by numerical scale with half and quarter sizes. In contrast, the UK, Australia, and South Africa use an alphabetical scale. 

For example, a US size 4 equals a UK size H, and a Japanese size 7. So, if you’re selling or buying rings internationally, it’s crucial to know the equivalent sizes in different countries. 

But, don’t worry, you don’t need to memorize all these conversions. You can refer to the ring size chart below to help you understand the equivalent sizes.

Ring Size Measurements & Conversion

The most commonly used measuring systems are the US and Canada sizing system, the UK, Ireland, Australia, and New Zealand sizing system, and the ISO standard based on the inner circumference of the ring (measured in millimeters). 

Understanding these different systems will help you cater to a global customer base, so it’s certainly worth investing some time in.

To make things easier, we’ve created a comprehensive international Ring Size Chart. 

This handy chart includes ring size measurements in both millimeters and inches, along with information about the different international ring sizing systems. 

It’s designed to help you quickly and easily convert ring sizes between different systems.

Ring Size Chart

INSIDE DIAMETER		INSIDE CIRCUMFERENCE		RING SIZES	RING SIZES	RING SIZES
MM	INCHES	MM (ISO SIZE)	INCHES	NUMERICAL (USA, CANADA, ETC.)	ALPHABETICAL (AUSTRALIA, UK, NZ, ETC.)	EUROPEAN (ISO MINUS 40MM)
11.6 mm	0.458″	36.5 mm	1.438″	0
11.8 mm	0.466″	37.2 mm	1.463″	1/4
12 mm	0.474″	37.8 mm	1.488″	2/4	A
12.2 mm	0.482″	38.4 mm	1.513″	3/4	A 1/2
12.4 mm	0.49″	39.1 mm	1.539″	1	B
12.6 mm	0.498″	39.7 mm	1.564″	1 1/4	B 1/2
12.9 mm	0.506″	40.4 mm	1.589″	1 1/2	C	0
13.1 mm	0.514″	41 mm	1.614″	1 3/4	C 1/2	1
13.3 mm	0.522″	41.6 mm	1.639″	2	D
13.5 mm	0.53″	42.3 mm	1.664″	2 1/4	D 1/2	2
13.7 mm	0.538″	42.9 mm	1.689″	2 1/2	E	3
13.9 mm	0.546″	43.5 mm	1.714″	2 3/4	E 1/2
14.1 mm	0.554″	44.2 mm	1.74″	3	F	4
14.3 mm	0.562″	44.8 mm	1.765″	3 1/4	F 1/2
14.3 mm	0.562″	45 mm	1.77″	–	G	5
14.5 mm	0.57″	45.5 mm	1.79″	3 1/2	G 1/2
14.7 mm	0.578″	46.1 mm	1.815″	3 3/4	H	6
14.9 mm	0.586″	46.7 mm	1.84″	4	H 1/2
15.1 mm	0.594″	47.4 mm	1.865″	4 1/4	I	7
15.3 mm	0.602″	48 mm	1.89″	4 1/2	I 1/2	8
15.5 mm	0.61″	48.7 mm	1.915″	4 3/4	J
15.7 mm	0.618″	49.3 mm	1.941″	5	J 1/2	9
15.9 mm	0.626″	49.9 mm	1.966″	5 1/4	K	10
16.1 mm	0.634″	50.6 mm	1.991″	5 1/2	K 1/2
16.3 mm	0.642″	51.2 mm	2.016″	5 3/4	L	11
16.5 mm	0.65″	51.8 mm	2.041″	6	L 1/2
16.7 mm	0.658″	52.5 mm	2.066″	6 1/4	M	12
16.9 mm	0.666″	53.1 mm	2.091″	6 1/2	M 1/2	13
17.1 mm	0.674″	53.8 mm	2.116″	6 3/4	N
17.3 mm	0.682″	54.4 mm	2.141″	7	N 1/2	14
17.5 mm	0.69″	55 mm	2.167″	7 1/4	O	15
17.7 mm	0.698″	55.7 mm	2.192″	7 1/2	O 1/2
17.9 mm	0.706″	56.3 mm	2.217″	7 3/4	P	16
18.1 mm	0.714″	56.9 mm	2.242″	8	P 1/2	17
18.3 mm	0.722″	57.6 mm	2.267″	8 1/4	Q
18.5 mm	0.73″	58.2 mm	2.292″	8 1/2	Q 1/2	18
18.7 mm	0.738″	58.9 mm	2.317″	8 3/4	R	19
18.9 mm	0.746″	59.5 mm	2.342″	9	R 1/2
19.2 mm	0.754″	60.1 mm	2.368″	9 1/4	S	20
19.4 mm	0.762″	60.8 mm	2.393″	9 1/2	S 1/2	21
19.6 mm	0.77″	61.4 mm	2.418″	9 3/4	T
19.8 mm	0.778″	62.1 mm	2.443″	10	T 1/2	22
20 mm	0.786″	62.7 mm	2.468″	10 1/4	U
20.2 mm	0.794″	63.3 mm	2.493″	10 1/2	U 1/2	23
20.4 mm	0.802″	64 mm	2.518″	10 3/4	V	24
20.6 mm	0.81″	64.6 mm	2.543″	11	V 1/2
20.8 mm	0.818″	65.2 mm	2.569″	11 1/4	W	25
21 mm	0.826″	65.9 mm	2.594″	11 1/2	W 1/2	26
21.2 mm	0.834″	66.5 mm	2.619″	11 3/4	X
21.4 mm	0.842″	67.2 mm	2.644″	12	X 1/2	27
21.6 mm	0.85″	67.8 mm	2.669″	12 1/4	Y	28
21.8 mm	0.858″	68.4 mm	2.694″	12 1/2	Y 1/2
22 mm	0.866″	69.1 mm	2.719″	12 3/4	Z	29
22.2 mm	0.874″	69.7 mm	2.744″	13	Z 1/2
22.4 mm	0.882″	70.3 mm	2.769″	13 1/4	Z1	30
22.6 mm	0.89″	71 mm	2.795″	13 1/2		31
22.8 mm	0.898″	71.6 mm	2.82″	13 3/4	Z2
23 mm	0.906″	72.3 mm	2.845″	14		32
23.2 mm	0.914″	72.9 mm	2.87″	14 1/4	Z3	33
23.4 mm	0.922″	73.5 mm	2.895″	14 1/2
23.6 mm	0.93″	74.2 mm	2.92″	14 3/4	Z4	34
23.8 mm	0.938″	74.8 mm	2.945″	15		35
24 mm	0.946″	75.4 mm	2.97″	15 1/4
24.2 mm	0.954″	76.1 mm	2.996″	15 1/2		36
24.4 mm	0.962″	76.7 mm	3.021″	15 3/4		37
24.6 mm	0.97″	77.4 mm	3.046″	16

How to Measure a Ring Size

1. Get a Ring Sizing Kit

The most precise way to measure a ring size is by using a ring sizing kit. These kits are inexpensive, easy to use, and widely available online or at your local jewelry store. 

Plus, they provide measurements in US, UK, and EU sizes, making them essential for any serious jewelry seller.

2. Measuring from an Existing Ring

If your customer already has a ring that fits them well, they can measure the diameter of this ring to determine their size. Simply place the ring over a ruler or a printable ring size chart and record the measurement.

3. Quick Measuring Methods: The String and Paper Technique

For a quick and easy method, you can use a piece of string or paper. Wrap it around the finger, mark where it overlaps, and then measure the length. 

This is a great method for a rough estimate, but always remember to recommend a professional measurement for the most accurate sizing.

4. Go to a Jeweler

When in doubt, recommend your customer to go to a professional jeweler. They have the expertise and tools to provide an accurate measurement.

Frequently Asked Questions about Ring Sizes

Let’s delve into the frequently asked questions about ring sizes that customers often encounter. This information will be beneficial for them, enabling them to make informed purchases.

When should you measure?

Ideally, measure the ring size at the end of the day when the fingers are at their largest.

How should a ring fit?

A perfect fit ring should slide over the knuckle with ease and have a slight resistance when removed.

What if your exact ring size isn’t available?

Always go for a larger size if the exact size isn’t available. It’s easier to resize a ring to a smaller size than to a larger one.

Should you go larger or smaller for wide band rings?

For wide band rings, opt for a slightly larger size as they tend to feel tighter.

How to deal with large knuckles?

Measure both the knuckle and the base of the finger, then choose a size in between.

Which measuring system to use?

Use the measuring system that is most common in your market region. For instance, if you’re in the US, use US sizes.

Can the ring be resized?

Most rings can be resized unless they are made of a material that is difficult to work with or if they have intricate designs.

In Conclusion

Understanding ring sizes and measurements might seem like a small detail, but it can make a big difference in your jewelry business. It’s all about meeting your customers’ needs and giving them the best possible experience. 

So, keep this guide handy, refer to our international Ring Size Chart, and you’ll be well on your way to mastering the art of ring sizing.

At Jewepiter, we’re all about practical, actionable and trustworthy advice that helps you build your successful jewelry brand. We’re here to make your life easier and your business stronger. Until next time, keep shining!