Convert US (us) to EU (eu) instantly. US ring size to European ring size conversion.
| Unit | Name | Value |
|---|---|---|
| uk | UK / Australia | — |
| eu | EU / Germany | — |
| mm | Circumference (mm) | — |
💡 Tip: Measure your finger circumference in mm — EU size = circumference in mm exactly. Divide by π (3.14159) to get diameter.
All standard sizes — with finger circumference and diameter for reference
| US / Canada | EU / Germany | Measurement |
|---|---|---|
| 3 | 44 | 44.2 mm circ / 14.1 mm dia |
| 3.5 | 45 | 45.5 mm circ / 14.5 mm dia |
| 4 | 46 | 46.8 mm circ / 14.9 mm dia |
| 4.5 | 47 | 48.0 mm circ / 15.3 mm dia |
| 5 | 48 | 49.3 mm circ / 15.7 mm dia |
| 5.5 | 49 | 50.6 mm circ / 16.1 mm dia |
| 6 | 51 | 51.9 mm circ / 16.5 mm dia |
| 6.5 | 52 | 53.1 mm circ / 16.9 mm dia |
| 7 | 54 | 54.4 mm circ / 17.3 mm dia |
| 7.5 | 55 | 55.7 mm circ / 17.7 mm dia |
| 8 | 57 | 57.0 mm circ / 18.1 mm dia |
| 8.5 | 58 | 58.3 mm circ / 18.6 mm dia |
| 9 | 59 | 59.5 mm circ / 18.9 mm dia |
| 9.5 | 61 | 60.8 mm circ / 19.4 mm dia |
| 10 | 62 | 62.1 mm circ / 19.8 mm dia |
| 10.5 | 63 | 63.4 mm circ / 20.2 mm dia |
| 11 | 65 | 64.6 mm circ / 20.6 mm dia |
| 12 | 67 | 67.2 mm circ / 21.4 mm dia |
| 13 | 70 | 69.7 mm circ / 22.2 mm dia |
Very rough: US 7 → EU 54. Use the chart — the relationship isn't linear at all ends.
US 6 = EU 51; US 7 = EU 54; US 8 = EU 57; US 9 = EU 59; US 10 = EU 62.
EU = circumference in mm. Measure your finger, that IS your EU size.
Converts US / Canada ring size to EU / Germany when purchasing from international online jewellers.
Converts customer-provided ring sizes to the sizing system used by their tools and ring blanks.
Converts a partner's known ring size to the size system used by an international jeweller.
Compares ring sizes from different measurement methods before placing a custom order.
Lists ring sizes in multiple systems on product pages for international customers.
Finds the correct local ring size equivalent when shopping for jewellery abroad.
US and Canadian ring sizes use a numerical scale (0–13+) where each half size corresponds to a finger circumference increment of about 1.3 mm. The system has no standardized international anchor — US size 7 ≈ 54.4 mm circumference, widely used as a reference for a 'medium' adult ring.
US ring sizing is the most common reference in online jewellery sales globally. Most international jewellers list US sizes alongside their local system. The average US women's ring size is 6–7; men's 9–10.
Interesting fact: Ring sizing developed from mandrel-based measurement — jewellers used tapered metal cones marked with arbitrary numbers. Different countries independently chose different numbering anchors, creating the incompatible systems that persist today.
EU (European/German) ring sizes are numerically equal to the finger circumference in millimeters. EU size 54 = 54 mm circumference = 17.2 mm diameter. This makes the EU system the most physically intuitive — you measure your finger and the EU size IS the circumference.
EU sizing is also called 'ISO sizing' and is standard in France, Germany, Spain, Italy, and most of continental Europe. EU sizes run approximately 44–76 for adults. Converting from EU to US or UK requires a size chart because the systems use different scales.
Interesting fact: Because EU size = circumference in mm, a jeweller anywhere in the world can produce a ring of the right size without any conversion — simply make the inner circumference equal to the EU size number in mm. This physical directness makes EU sizing the most international reference.
Ring sizes are not internationally standardized. US/Canada use a numerical scale (0–13); UK/Australia use letters (A–Z+); EU/Germany use circumference in mm (the most physically direct system). The universal anchor: US 7 = UK N = EU 54 = 54.4 mm circumference = 17.3 mm diameter.
For the most accurate measurement, wrap a strip of paper around the base of your finger, mark the overlap, and measure in mm — that IS your EU size. Always measure at the end of the day.