Complete 2026 women's ring size conversion — UK · US · EU · French · German · Japanese · Swiss · Australian sizing systems with MM diameter & circumference, interactive converter and expert tips.
Alphabet letters A–Z+6. Half sizes standard. Based on BS EN 28653:1993.
Women's: H–RNumbers ½–15 with quarter increments. Uses British inch basis. Most jewellery sites default to this.
Women's: 4–9Number = inner circumference in mm. Simplest system — no conversion needed when you have mm.
Women's: 47–59EU size minus 40. So EU 51 = French 11. Used across France, Italy, Spain, Portugal and parts of Latin America.
Women's: 7–19Numbers 1–28. Used across East Asia. JIS B 4803 standard. Widely used on Asian shopping platforms.
Women's: 7–18Numbers ½–37.5. Used in Switzerland, Netherlands. Common on Swiss and Dutch jewellery platforms.
Women's: 7–18.5| 🇬🇧 UK | 🇦🇺 AU/NZ | 🇺🇸 US | 🇩🇪 EU | 🇫🇷 French | 🇩🇪 German | 🇯🇵 Japan | 🇨🇭 Swiss | 📐 Diam. MM | ⭕ Circ. MM | Category |
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Find the country or platform you're buying from. Amazon UK / Etsy UK → UK column. US / Canadian sites → US column. Most European retailers → EU column.
Locate your known size in its column, then read across the same row to find the equivalent in any other system.
When in doubt, measure your circumference in mm and use that value directly. EU size = circumference in mm. All other systems convert from there.
Enter any size in any system and get all six conversions plus MM values instantly — the fastest way to cross-check before ordering.
Australian and New Zealand ring sizes use exactly the same letter system as the UK. No conversion needed — UK L = AU L = NZ L.
Always check if the retailer offers half sizes. A UK L½ (16.5mm) is meaningfully different from L (16.3mm). If not available, go up — never down.
The EU size is simply the inner circumference in whole mm. EU 51 = 51mm circumference = UK L. When converting, the EU number is the most direct bridge between all systems.
The UK letter system is used identically in Australia, New Zealand, South Africa and Ireland. No conversion needed between these five countries — UK L is AU L is NZ L.
US size numbers and UK size letters look different but are completely unrelated. UK size 6 does not exist — UK uses letters. US "L" does not exist — US uses numbers. Always check the system first.
The safest approach when ordering from a foreign retailer: quote your inner circumference in mm. It's the universal measurement understood by every jeweller worldwide — no ambiguity.
Quick mental shortcut: French size = EU size − 40. So if a French retailer says "taille 11", that's EU 51 = UK L = US 6. Works for Italian and Spanish sizing too — same formula.
Japanese sizes start from 1 and the system runs slightly smaller than EU equivalents. Japan size 10 = UK L (EU 51), but always double-check with mm on Japanese shopping platforms like Rakuten.
When converting produces a value between two sizes, always choose the larger size — especially in a system you're less familiar with. Slightly loose is wearable; too tight is painful and potentially unsafe.
ASOS, Etsy and Amazon list rings in the seller's country system. A US Etsy seller uses US sizes; a UK seller uses UK letters. Always check the seller location before using a size chart.
If ordering internationally and unsure, size up by half a step. Most rings can be resized down (removing metal) more easily and cheaply than sizing up. A local UK jeweller can resize for £30–£80.