Quick answer: A European ring size is the inside circumference of the ring in millimetres. EU 52 is about US 6, EU 54 is about US 7 (6.75 exactly), EU 56 is about US 7.5–7.75, EU 58 is about US 8.5, and EU 60 is about US 9–9.25.
What a European ring size actually measures
The European system follows the international standard ISO 8653, which defines ring sizes by the inner circumference of the ring in millimetres. So an EU 54 ring has an inside circumference of 54 mm, and an inside diameter of about 17.2 mm (circumference divided by π). You can read more about the standard on Wikipedia’s ring size page or the ISO 8653:2016 listing.
US sizes work differently: they are numbered steps, with each whole size adding about 2.55 mm of circumference. That is why there is no exact one-to-one match for every EU number, and why converting usually lands between two US sizes.
European to US ring size chart
The “nearest quarter” column is the closest US quarter-size; the “nearest half” column is the closest half-size, which is how most US jewellers stock rings. Values are calculated from the standard circumference steps and rounded.
| EU / ISO size | Inside diameter | US (nearest quarter) | US (nearest half) |
|---|---|---|---|
| EU 46 (46 mm) | 14.6 mm | US 3.75 | US 3.5 |
| EU 48 (48 mm) | 15.3 mm | US 4.5 | US 4.5 |
| EU 49 (49 mm) | 15.6 mm | US 5 | US 5 |
| EU 50 (50 mm) | 15.9 mm | US 5.25 | US 5.5 |
| EU 51 (51 mm) | 16.2 mm | US 5.75 | US 5.5 |
| EU 52 (52 mm) | 16.6 mm | US 6 | US 6 |
| EU 53 (53 mm) | 16.9 mm | US 6.5 | US 6.5 |
| EU 54 (54 mm) | 17.2 mm | US 6.75 | US 7 |
| EU 55 (55 mm) | 17.5 mm | US 7.25 | US 7 |
| EU 56 (56 mm) | 17.8 mm | US 7.75 | US 7.5 |
| EU 57 (57 mm) | 18.1 mm | US 8 | US 8 |
| EU 58 (58 mm) | 18.5 mm | US 8.5 | US 8.5 |
| EU 59 (59 mm) | 18.8 mm | US 8.75 | US 9 |
| EU 60 (60 mm) | 19.1 mm | US 9.25 | US 9 |
| EU 61 (61 mm) | 19.4 mm | US 9.5 | US 9.5 |
| EU 62 (62 mm) | 19.7 mm | US 10 | US 10 |
| EU 64 (64 mm) | 20.4 mm | US 10.75 | US 11 |
| EU 66 (66 mm) | 21.0 mm | US 11.5 | US 11.5 |
If you want to check any of these against our full tables, see the US ring size chart and the world ring size conversion chart.
The most-searched EU sizes, answered
- EU 48: about US 4.5.
- EU 50: about US 5.25 (many stores sell it as 5.5).
- EU 52: about US 6. This is the closest match of any common size.
- EU 54: about US 6.75, usually sold as US 7.
- EU 56: between US 7.5 and 7.75.
- EU 58: about US 8.5.
- EU 60: about US 9 to 9.25.
- EU 62: about US 10. EU 64: about US 10.75–11.
When a “European” size is not ISO
Here is where conversions go wrong. Several countries label their sizes differently, and a number on a product page may not be the ISO circumference at all.
- Italy, Spain and Switzerland: sizes are often the circumference minus 40. An Italian size 14 is therefore a 54 mm ring (EU 54), not a 14 mm one.
- Germany: sizes are commonly based on the inside diameter in mm (for example 17 or 18), not the circumference. A German 17 is closer to US 6.5, not EU 17.
- Russia and some online marketplaces: a size like 17, 18 or 19 usually means diameter in mm, often rounded to the nearest half.
- Japan: uses its own numbered scale that does not match the EU or US ones. See the Japan ring size chart.
Quick test: if the number is between roughly 44 and 70, it is almost certainly an ISO circumference. If it is between about 14 and 24, it is probably a diameter or a minus-40 size.
How to convert any EU size yourself
- Take the EU size in mm (for example 57).
- Subtract about 36.5 mm, the circumference of a US size 0 on our scale.
- Divide by 2.55. That gives 8.0 for 57 mm.
- Round to the nearest quarter or half size, as the shop sells it.
This gives a good estimate, but small differences between brands and between sizing standards mean a few tenths of a size either way.
Ordering from a European brand
If you are buying from a European brand and your size falls between two numbers, most jewellers advise going up, not down, particularly for wider bands. Pandora, for example, uses EU-style numbering; our Pandora ring size chart covers how its sizes map to US. To find your size in the first place, use a printable ring sizer or read ring size chart in cm and inches.
Frequently asked questions
What is ring size 52 in US?
EU 52 is about US 6. A 52 mm inside circumference corresponds to roughly 16.6 mm inside diameter.
What is ring size 54 in US?
EU 54 is about US 6.75, and is normally sold as a US 7.
What is ring size 58 in US?
EU 58 is about US 8.5.
What is ring size 60 in US?
EU 60 is between US 9 and 9.25.
Is EU ring size the same as the German or Italian size?
Not always. Italian and Spanish sizes are often the circumference minus 40, and German sizes are often based on the diameter. Always check what the number refers to.
Can I convert my UK size to EU?
Yes, but it takes two steps via the circumference. The UK ring size chart shows the circumference for each letter.
