The complete Australia to UK ring size conversion guide 2026 — Australian and UK ring sizes use the identical A–Z+2 letter system, full AU/UK to US conversion, AU/UK to EU conversion, mm diameter and circumference reference, women's and men's average sizes, and free conversion calculator
Australian ring sizes use exactly the same A–Z+2 alphabetical letter system as UK ring sizes — with the same circumference and diameter values at every letter size. There is no conversion needed between Australian and UK ring sizes. A ring labelled AU Size N is exactly the same as a ring labelled UK Size N — the same circumference (53.8mm), the same inner diameter (17.1mm), and the same fit on the finger.
The conversion tables on this page are needed when converting from US sizes (used by American online retailers), from EU/Continental sizes (used by European jewellers), or from millimetre measurements — into the AU/UK letter system used by Australian and British jewellers.
Australian and British jewellers both use the A–Z+2 alphabetical ring sizing system. Every AU letter size is identical to the same UK letter size in circumference, diameter and fit. The conversion chart on this page is for shoppers buying from US, European or international retailers who use different sizing standards — not for AU-to-UK conversion itself.
🇺🇸 US 6.5 | 🇪🇺 EU 52
Circumference: 53.8mm
Diameter: 17.1mm
Ring finger, left hand
🇺🇸 US 9.5 | 🇪🇺 EU 61
Circumference: 61.4mm
Diameter: 19.56mm
Ring finger, left hand
🇺🇸 US 5.5–7 | 🇪🇺 EU 50–54
Circumference: 51.2–55.1mm
Diameter: 16.3–17.5mm
Most common range
🇺🇸 US 9–10.5 | 🇪🇺 EU 60–64
Circumference: 60.2–64.0mm
Diameter: 19.1–20.37mm
Most common range
Australian ring sizes are identical to UK ring sizes — the AU/UK column below is the same for both countries. Use this chart when you need to convert a US size (from American retailers like Tiffany US, Etsy US, Amazon US) or an EU/Continental size (from European retailers) into your AU or UK letter size.
| 🇦🇺 AU / 🇬🇧 UK | Circ. (mm) | Diam. (mm) | Circ. (cm) | Circ. (inches) | 🇺🇸 US Size | 🇪🇺 EU Size | Best For |
|---|---|---|---|---|---|---|---|
| A | 37.8 mm | 11.9 mm | 3.78 cm | 1.488″ | — | 37 | Children / XS |
| B | 39.1 mm | 12.3 mm | 3.91 cm | 1.539″ | 1 | 38 | Children / XS |
| C | 40.4 mm | 12.7 mm | 4.04 cm | 1.590″ | 1.5 | 40 | XS Women |
| D | 41.7 mm | 13.1 mm | 4.17 cm | 1.642″ | 2 | 41 | Small Women |
| E | 42.9 mm | 13.5 mm | 4.29 cm | 1.689″ | 2.5 | 42 | Small Women |
| F | 44.2 mm | 13.9 mm | 4.42 cm | 1.740″ | 3 | 43 | Small Women |
| G | 45.5 mm | 14.3 mm | 4.55 cm | 1.791″ | 3.5 | 45 | Women |
| H | 46.8 mm | 14.7 mm | 4.68 cm | 1.843″ | 4 | 46 | Women |
| I | 48.0 mm | 15.1 mm | 4.80 cm | 1.890″ | 4.5 | 47 | Women |
| J | 48.7 mm | 15.5 mm | 4.87 cm | 1.917″ | 4.75 | 48 | Women |
| K | 50.0 mm | 15.9 mm | 5.00 cm | 1.969″ | 5 | 49 | Women |
| L | 51.2 mm | 16.3 mm | 5.12 cm | 2.016″ | 5.5 | 50 | Women |
| M | 52.5 mm | 16.7 mm | 5.25 cm | 2.067″ | 6 | 51 | Women |
| N ⭐ | 53.8 mm | 17.1 mm | 5.38 cm | 2.118″ | 6.5 | 52 | Women's Avg ⭐ |
| O ⭐ | 55.1 mm | 17.5 mm | 5.51 cm | 2.169″ | 7 | 54 | Women Popular |
| P ⭐ | 56.3 mm | 17.9 mm | 5.63 cm | 2.217″ | 7.5 | 55 | Women Popular |
| Q | 57.6 mm | 18.2 mm | 5.76 cm | 2.268″ | 8 | 57 | Slim Men |
| R | 58.9 mm | 18.6 mm | 5.89 cm | 2.319″ | 8.5 | 58 | Lean Men |
| S | 60.2 mm | 19.1 mm | 6.02 cm | 2.370″ | 9 | 60 | Avg Slim Men |
| T ⭐ | 61.4 mm | 19.56 mm | 6.14 cm | 2.417″ | 9.5 | 61 | Men's Avg ⭐ |
| U ⭐ | 62.7 mm | 19.96 mm | 6.27 cm | 2.469″ | 10 | 63 | Men Popular |
| V ⭐ | 64.0 mm | 20.37 mm | 6.40 cm | 2.520″ | 10.5 | 64 | Men Popular |
| W | 65.3 mm | 20.78 mm | 6.53 cm | 2.571″ | 11 | 65 | Athletic Men |
| X | 66.6 mm | 21.18 mm | 6.66 cm | 2.622″ | 11.5 | 67 | Broad Men |
| Y | 67.8 mm | 21.59 mm | 6.78 cm | 2.669″ | 12 | 68 | Large Build |
| Z | 68.5 mm | 21.79 mm | 6.85 cm | 2.697″ | 12.5 | 69 | XL Build |
| Z+1 | 69.7 mm | 22.20 mm | 6.97 cm | 2.744″ | 13 | 70 | XL Custom |
| Z+2 | 72.3 mm | 23.01 mm | 7.23 cm | 2.846″ | 13.5 | 72 | Custom |
American retailers use the US ring size system — a numeric scale roughly ranging from 3 to 13.5. When ordering from a US retailer, find your AU/UK letter size in the conversion chart above and use the corresponding US size listed. Common women's sizes: AU/UK L = US 5.5 · AU/UK N = US 6.5 · AU/UK P = US 7.5. Common men's sizes: AU/UK R = US 8.5 · AU/UK T = US 9.5 · AU/UK V = US 10.5.
When US sizes are listed in half sizes (6.5, 7.5) — always select the listed half size rather than rounding to a whole number. US half sizes correspond precisely to specific AU/UK sizes in the conversion chart. If the US retailer only offers whole sizes and your AU/UK size falls between two — select the larger whole US size (e.g. if AU/UK N = US 6.5 and only whole sizes are available, select US 7 rather than US 6).
European and Continental ring sizes use a numeric system based on the inner circumference of the ring in millimetres (e.g. EU 52 = 52mm circumference). When ordering from a European retailer — find your AU/UK letter size in the conversion chart above and use the EU number listed. Common women's sizes: AU/UK L = EU 50 · AU/UK N = EU 52 · AU/UK P = EU 55. Common men's sizes: AU/UK R = EU 58 · AU/UK T = EU 61 · AU/UK V = EU 64.
Note: Some EU listings show sizes as ISO/DIN numbers which match directly to circumference in mm. Others use French/German systems which use the same numeric scale. In all cases, the EU column in the conversion chart above provides the correct conversion value.
In addition to Australia and the UK, New Zealand and South Africa also use the identical A–Z+2 alphabetical ring sizing system. A ring sized in New Zealand or South Africa will fit exactly the same as the same letter size purchased in Australia or the UK — no conversion is needed between any of these four countries. This shared system also extends to Ireland. The AU/UK letter system is the most widely used ring sizing standard in the Southern Hemisphere and the Commonwealth.