Convert EU (eu) to UK (uk) instantly. EU ring size to UK ring size conversion.
| Unit | Name | Value |
|---|---|---|
| us | US / Canada | — |
| uk | UK / Australia | — |
| 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
| EU / Germany | UK / Australia | Measurement |
|---|---|---|
| 44 | F | 44.2 mm circ / 14.1 mm dia |
| 45 | G | 45.5 mm circ / 14.5 mm dia |
| 46 | H | 46.8 mm circ / 14.9 mm dia |
| 47 | I | 48.0 mm circ / 15.3 mm dia |
| 48 | J | 49.3 mm circ / 15.7 mm dia |
| 49 | K | 50.6 mm circ / 16.1 mm dia |
| 51 | L | 51.9 mm circ / 16.5 mm dia |
| 52 | M | 53.1 mm circ / 16.9 mm dia |
| 54 | N | 54.4 mm circ / 17.3 mm dia |
| 55 | O | 55.7 mm circ / 17.7 mm dia |
| 57 | P | 57.0 mm circ / 18.1 mm dia |
| 58 | Q | 58.3 mm circ / 18.6 mm dia |
| 59 | R | 59.5 mm circ / 18.9 mm dia |
| 61 | S | 60.8 mm circ / 19.4 mm dia |
| 62 | T | 62.1 mm circ / 19.8 mm dia |
| 63 | U | 63.4 mm circ / 20.2 mm dia |
| 65 | V | 64.6 mm circ / 20.6 mm dia |
| 67 | X | 67.2 mm circ / 21.4 mm dia |
| 70 | Z | 69.7 mm circ / 22.2 mm dia |
EU size ≈ circumference in mm; UK letters cover ~1.25 mm each.
EU 51 = UK L; EU 54 = UK N; EU 57 = UK P; EU 59 = UK R.
String around finger → mm = EU size → use chart for UK letter.
Converts EU / Germany ring size to UK / Australia 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.
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.
UK and Australian ring sizes use an alphabetical system (A–Z+) where each letter corresponds to a finger circumference increment of about 1.25 mm. The system is also used in Ireland, New Zealand, and South Africa.
UK letter sizing is intuitive for half sizes — 'F½' is between F and G. The most common UK women's sizes are L–P; men's P–T. UK size N ≈ US size 7 ≈ EU 54 — the most common global reference size.
Interesting fact: The UK ring sizing system is also used in Australia and Ireland despite metrication — a legacy of the British Imperial measurement tradition that persists in the jewellery trade even though lengths are now measured in mm.
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.