Your Essential Global Ring Size Chart with Ring Measurements Explained

Have you ever found the perfect ring online, perhaps from a beautiful boutique in Paris or a cool designer in Berlin, only to get stuck at the checkout? The dreaded “Select Size” dropdown menu appears, and suddenly you are looking at options like “Size 52,” “Size P,” or “Size 16.5.”

If you are used to just knowing you are a “Size 7,” this international jumble of numbers and letters can be incredibly frustrating. It stops many people from buying the jewelry they love because nobody wants the hassle of returning an ill-fitting ring internationally.

We are here to fix that confusion right now.

The truth is that there isn’t one single global standard for ring sizes. Different regions have developed their own systems over time. However, there is one universal language that connects them all: millimeters.

This guide will break down the major international systems and provide you with a definitive ring size chart with ring measurements in millimeters so you can order with total confidence no matter where the jeweler is located.

The Two Golden Measurements

Before we look at the chart, you need to understand the secret to getting this right. Ignore the confusing labels like “US Size 6” or “UK Size L” for just a moment.

The only thing that matters is the actual physical measurement of your finger or the ring.

There are two ways to measure a ring in millimeters (mm):

1. Diameter: The distance straight across the inside middle of the ring.
2. Circumference: The total distance around the inside circle of the ring.

If you know one of these two measurements in millimeters, you can convert it to any size system in the world using our chart below.

A Quick Tour of Global Ring Systems

Why is it so complicated? It is simply because different countries decided to measure different parts of the ring as their standard.

Here is a simple breakdown of how the major players do it.

1. The European Systems (It’s Not All the Same!)

People often assume “European Sizing” is one thing, but it actually splits into three distinct methods depending on the country.

• France and Belgium (The Easiest System): These countries use the ISO standard. Their ring size is simply the inner circumference in millimeters. If your finger measures 52mm around, you are a Size 52. Simple.
• Germany and The Netherlands (The Precision System): These countries base their sizes on the inner diameter in millimeters. If the inside width of the ring is exactly 17.5mm, your size is 17.5. You will often see these sizes listed in half-millimeter steps, like 17, 17.5, and 18.
• Italy and Spain (The “Minus 40” System): This is a regional standard that requires a tiny bit of math. They take the inner circumference in millimeters and subtract 40 to get the size. For example, a 52mm circumference minus 40 equals a Size 12.

2. The US and UK Systems

These systems do not correspond directly to millimeter measurements in a logical way, which is why they are confusing for international buyers.

• US and Canada: This system uses numerical sizes (like 6, 7, 8) with quarter and half sizes in between.
• UK, Australia, and New Zealand: This system uses an alphabetical scale (A to Z). The steps between letters are roughly half sizes in the US system.

International Ring Size Chart with Ring Measurements

Use this chart to find your match. We recommend finding your measurement in the “Diameter” or “Circumference” columns first, and then seeing which international size aligns with it.

Please note that US and UK sizes sometimes fall slightly between the precise millimeter markings used in Europe. We have grouped them with their closest match.

Tips for Getting the Right Measurement

Having the chart is great, but you still need accurate millimeter numbers to use it. Here is how to get them.

Tip 1: The “Existing Ring” Method (Best for Diameter)

If you already have a ring that fits the exact finger you are buying for, this is the easiest method. Take a ruler with millimeter markings. Place the ring on top of the ruler. Measure the inside circle across the widest part. Do not include the metal thickness of the ring itself. That millimeter measurement is your diameter.

Tip 2: The “Paper Strip” Method (Best for Circumference)

Cut a thin, non-stretchy strip of paper. Wrap it around the base of your finger where the ring will sit. Make sure it is snug but not tight, and ensure it can slide over your knuckle. Mark the spot where the paper overlaps with a pen. Lay the paper flat against a ruler and measure the distance to the mark in millimeters. That is your circumference.

Tip 3: Timing is Everything

Your fingers actually change size during the day based on temperature and activity. The best time to measure your finger is at the end of the day when your fingers are at their largest. Do not measure when your hands are very cold, as your fingers will be smaller than usual.

Conclusion

Buying rings internationally opens up a world of unique designs and craftsmanship. Don’t let the confusing numbers scare you away. By focusing on the millimeter measurements and using this ring size chart with ring details, you can order that dream piece of jewelry knowing it will be the perfect fit.

If you don’t have a ruler handy or just want a faster, digital solution, you can actually measure your ring size directly on your screen. Simply visit Ring Sizer Tool Online for an instant measurement.