A ring size chart converts your finger's inside diameter or circumference in millimeters into a US, UK, or EU ring size. Measure the inside diameter of a ring that fits (or your finger's circumference), find that measurement in the chart below, and read across to your size in any system. For example, an inside diameter of 17.3 mm (54.4 mm circumference) is a US 7, UK N½, and EU 54.
This is our complete, printable ring size chart, with US, UK, and EU sizes lined up against the inside diameter and circumference in millimeters — everything you need to convert between systems or turn a measurement into a size. If you haven't measured yet, our step-by-step how to measure ring size at home guide shows you how; this page is the reference table to use alongside it. Bookmark or print it, then when you know your size, browse our collection of his and hers wedding bands.
1. The full ring size chart
Find your inside diameter or circumference in millimeters on the left, then read across to your size in each system. Measurements are rounded and approximate — always confirm against the exact ring style before ordering.
| Diameter (mm) | Circumference (mm) | US / Canada | UK / Australia | Europe (EU) |
|---|---|---|---|---|
| 14.0 | 44.2 | 3 | F | 44 |
| 14.4 | 45.5 | 3½ | G | 45 |
| 14.8 | 46.8 | 4 | H½ | 47 |
| 15.2 | 48.0 | 4½ | I½ | 48 |
| 15.7 | 49.3 | 5 | J½ | 49 |
| 16.1 | 50.6 | 5½ | L | 51 |
| 16.5 | 51.9 | 6 | L½ | 52 |
| 16.9 | 53.1 | 6½ | N | 53 |
| 17.3 | 54.4 | 7 | N½ | 54 |
| 17.7 | 55.7 | 7½ | P | 56 |
| 18.1 | 57.0 | 8 | P½ | 57 |
| 18.5 | 58.3 | 8½ | Q½ | 58 |
| 18.9 | 59.5 | 9 | R½ | 59 |
| 19.4 | 60.8 | 9½ | S½ | 61 |
| 19.8 | 62.1 | 10 | T½ | 62 |
| 20.2 | 63.4 | 10½ | U½ | 63 |
| 20.6 | 64.6 | 11 | V½ | 65 |
| 21.0 | 65.9 | 11½ | W½ | 66 |
| 21.4 | 67.2 | 12 | Y | 67 |
| 21.8 | 68.5 | 12½ | Z | 68 |
| 22.2 | 69.7 | 13 | Z½ | 70 |
Diameter = the distance straight across the inside of the ring. Circumference = the distance around the inside (or around your finger). UK/EU equivalents are approximate; conversions can vary slightly by manufacturer.
Shop his and hers wedding bands →2. How to use the chart
There are two easy ways to land on a size. If you have a ring that already fits the correct finger, measure its inside diameter in millimeters and find that number in the first column — the row gives your size in every system. If you've measured your finger's circumference (by wrapping a strip of paper or string around it), use the second column instead. Either way, if your measurement falls between two rows, choose the larger size so the ring clears your knuckle.
For the full method behind taking those measurements accurately — including the paper-strip technique, printable sizers, and the timing that affects finger size — see our ring sizing guide. This chart and that guide are designed to be used together: the guide tells you how to measure, this page tells you what the measurement means.
3. US, UK, and EU sizes explained
Ring sizing systems differ by region, which is why a conversion chart matters when you're buying from an international jeweler. The US and Canada use a numeric scale, typically from about 3 to 13, including half sizes. The UK and Australia use an alphabetic scale, running through the letters (with half sizes) from around F upward. Europe generally uses the ISO standard, where the size number is simply the inside circumference in millimeters — so an EU 54 has a 54 mm inner circumference.
Because the underlying measurement (the actual size of your finger) is the same, any measurement in millimeters can be converted to all three systems, which is exactly what the chart above does. When in doubt, the millimeter measurement is the most precise and universal reference, so it's worth recording yours.
4. Printing the chart accurately
This page is designed to print cleanly for reference. If you print it to measure against — for instance, laying a ring over printed circles or checking a paper sizer — the single most important thing is to print at 100% scale (sometimes labeled "Actual size"), never "Fit to page," which stretches or shrinks the measurements and makes them inaccurate. After printing, verify the scale by measuring a known distance with a ruler before relying on it. If you'd like a dedicated printable sizer tool as well, just ask our team.
5. Sizing tips
A few quick reminders that make the chart more reliable. Measure your finger at the end of the day and at a normal temperature, since fingers are smallest in the morning and in the cold. Take the measurement two or three times and average it. Remember that wider bands fit more snugly, so consider sizing up a little for a band of 6 mm or more, and that comfort-fit bands run about half a size smaller than standard fit. And always size the correct finger on the correct hand — your dominant hand is often slightly larger. These and more are covered in full in our how to measure ring size at home guide, and in the wider context of choosing a band in our wedding band buying guide.
Explore his and hers wedding bands →6. Frequently asked questions
- How do I read a ring size chart?
- Find your finger's inside diameter or circumference in millimeters in the left columns, then read across to your size in the US, UK, or EU system. If you're between two rows, choose the larger size so the ring clears your knuckle.
- What is a size 7 ring in mm?
- A US size 7 is approximately 17.3 mm inside diameter and 54.4 mm inside circumference, equivalent to a UK N½ and an EU 54.
- How do I convert US ring sizes to UK or EU?
- Use the chart above — each row lines up the US, UK, and EU size for the same millimeter measurement. The EU size is simply the inside circumference in millimeters, while UK sizes use letters.
- Is ring diameter or circumference used for sizing?
- Both work — diameter is the distance across the inside of a ring, circumference is the distance around it (or around your finger). The chart lists both so you can use whichever you measured.
- How do I measure my ring size to use this chart?
- Wrap paper or string around your finger for circumference, or measure the inside diameter of a ring that fits. Our ring sizing guide walks through every method step by step.
- Can I print this ring size chart?
- Yes — print at 100% scale (Actual size), not "Fit to page," and verify with a ruler afterward so the measurements stay accurate.
