Find Your Perfect Fit: International Ring Size Conversion Chart
Choosing the perfect ring, whether for an engagement, wedding, or everyday wear, starts with getting the size right. At Simon Wright Jewellery, we understand that a flawless fit is essential. That’s why we’ve created a detailed ring size conversion chart to help you confidently convert between different international sizing systems. Whether you're searching for a UK ring size, a US ring size, or need to convert US to UK ring size, our guide ensures your best chance of a perfectly fitting ring, no matter where in the world you shop.
Why Ring Size Conversion Matters
Ring sizes vary significantly across countries, which can make shopping for jewellery internationally a bit confusing. There’s no universal sizing system - each region uses its own scale, making understanding these differences vital - especially if you’re shopping online or purchasing a gift for someone overseas. That’s where our ring size conversion chart comes in handy.
Here are the most common systems you’ll encounter:
United Kingdom and Australia: Alphabetical sizing, from A to Z+.
Europe: Sizes based on the ring’s inner circumference or diameter in mm.
United States, Canada, and Mexico: Numeric sizing, generally from size 3 to 13.
Japan and China: Use a numeric system based on finger circumference.
The Simon Wright Jewellery Ring Sizes Conversion Chart
To simplify the process, we've created a comprehensive ring sizing conversion chart covering all major international systems. Whether you're converting UK to US ring size or trying to find a European equivalent, our easy-to-use chart removes the guesswork.
If you’re unsure of your and your significant other’s ring size, or don’t know how to measure a ring size at home, why not use our free printable UK ring size chart? From there, you can convert to any other size.
Need help finding the right size? Explore our full ring size conversion chart today.
| Inside Diameter | Inside Circumference | Sizes | |||||||
|---|---|---|---|---|---|---|---|---|---|
| mm | Inches | mm | Inches | UK & AUS | US & CA | German | French & Russian | Swiss | Japanese |
| 9.91 | 0.39 | 31.13 | 1.22 | - | 0 | - | - | - | - |
| 10.72 | 0.442 | 33.68 | 1.39 | - | 0 | - | - | - | - |
| 11.53 | 0.454 | 36.22 | 1.43 | - | 0 | - | - | - | - |
| 11.95 | 0.474 | 37.54 | 1.49 | A | 0.5 | - | - | - | - |
| 12.18 | 0.482 | 38.26 | 1.51 | A 1/2 | 0.75 | - | - | - | - |
| 12.37 | 0.487 | 38.86 | 1.53 | B | 1 | - | - | - | 1 |
| 12.6 | 0.496 | 39.58 | 1.56 | B 1/2 | 1.25 | - | - | - | - |
| 12.78 | 0.503 | 40.15 | 1.58 | C | 1.5 | - | - | - | - |
| 13 | 0.512 | 40.84 | 1.61 | C 1/2 | 1.75 | - | - | - | - |
| 13.21 | 0.52 | 41.5 | 1.63 | D | 2 | 13.5 | 41.5 | 1.5 | 2 |
| 13.41 | 0.528 | 42.13 | 1.66 | D 1/2 | 2.25 | - | - | - | - |
| 13.61 | 0.536 | 42.76 | 1.68 | E | 2.5 | 13.75 | 42.75 | 2.75 | 3 |
| 13.83 | 0.544 | 43.45 | 1.71 | E 1/2 | 2.75 | - | - | - | - |
| 14.05 | 0.553 | 44.14 | 1.74 | F | 3 | 14 | 44 | 4 | 4 |
| 14.15 | 0.557 | 44.45 | 1.75 | F 1/2 | 3.125 | - | - | - | - |
| 14.25 | 0.561 | 44.77 | 1.76 | F 3/4 | 3.25 | - | - | - | - |
| 14.36 | 0.565 | 45.11 | 1.77 | G | 3.375 | - | 45.25 | 5.25 | 5 |
| 14.45 | 0.569 | 45.4 | 1.79 | G 1/4 | 3.5 | 14.5 | - | - | - |
| 14.56 | 0.573 | 45.74 | 1.8 | G 1/2 | 3.625 | - | - | - | 6 |
| 14.65 | 0.577 | 46.02 | 1.81 | H | 3.75 | - | 46.5 | 6.5 | - |
| 14.86 | 0.585 | 46.68 | 1.84 | H 1/2 | 4 | 15 | - | - | 7 |
| 15.04 | 0.592 | 47.25 | 1.86 | I | 4.25 | - | 47.75 | 7.75 | - |
| 15.27 | 0.601 | 47.97 | 1.89 | I 1/2 | 4.5 | 15.25 | - | - | 8 |
| 15.4 | 0.606 | 48.38 | 1.9 | J | 4.625 | 15.5 | 49 | 9 | - |
| 15.53 | 0.611 | 48.79 | 1.92 | J 1/4 | 4.75 | - | - | - | - |
| 15.7 | 0.618 | 49.32 | 1.94 | J 1/2 | 5 | 15.75 | - | - | 9 |
| 15.8 | 0.622 | 49.64 | 1.95 | K | 5.125 | - | 50 | 10 | - |
| 15.9 | 0.626 | 49.95 | 1.97 | K 1/4 | 5.25 | - | - | - | - |
| 16 | 0.63 | 50.27 | 1.98 | K 1/2 | 5.375 | - | - | - | 10 |
| 16.1 | 0.634 | 50.58 | 1.99 | L | 5.5 | 16 | 51.75 | 11.75 | - |
| 16.3 | 0.642 | 51.21 | 2.02 | L 1/4 | 5.75 | - | - | - | - |
| 16.41 | 0.646 | 51.55 | 2.03 | L 1/2 | 5.875 | - | - | - | - |
| 16.51 | 0.65 | 51.87 | 2.04 | M | 6 | 16.5 | 52.75 | 12.75 | 12 |
| 16.71 | 0.658 | 52.5 | 2.07 | M 1/2 | 6.25 | - | - | - | - |
| 16.92 | 0.666 | 53.16 | 2.09 | N | 6.5 | 17 | 54 | 14 | 13 |
| 17.13 | 0.674 | 53.82 | 2.12 | N 1/2 | 6.75 | - | - | - | - |
| 17.35 | 0.683 | 54.51 | 2.15 | O | 7 | 17.25 | 55.25 | 15.25 | 14 |
| 17.45 | 0.687 | 54.82 | 2.16 | O 1/2 | 7.25 | - | - | - | - |
| 17.75 | 0.699 | 55.76 | 2.2 | P | 7.5 | 17.75 | 56.5 | 16.5 | 15 |
| 17.97 | 0.707 | 56.45 | 2.22 | P 1/2 | 7.75 | - | - | - | - |
| 18.19 | 0.716 | 57.15 | 2.25 | Q | 8 | 18 | 57.75 | 17.75 | 16 |
| 18.35 | 0.722 | 57.65 | 2.27 | Q 1/2 | 8.25 | - | - | - | - |
| 18.53 | 0.729 | 58.21 | 2.29 | Q 3/4 | 8.5 | 18.5 | - | - | 17 |
| 18.61 | 0.733 | 58.47 | 2.3 | R | 8.625 | - | 59 | 19 | - |
| 18.69 | 0.736 | 58.72 | 2.31 | R 1/4 | 8.75 | - | - | - | - |
| 18.8 | 0.74 | 59.06 | 2.32 | R 1/2 | 8.875 | - | - | - | - |
| 18.89 | 0.748 | 59.34 | 2.35 | R 3/4 | 9 | 19 | - | - | 18 |
| 19.1 | 0.752 | 60 | 2.36 | S | 9.125 | - | 60.25 | 20.25 | - |
| 19.22 | 0.757 | 60.38 | 2.38 | S 1/4 | 9.25 | - | - | - | - |
| 19.31 | 0.76 | 60.66 | 2.39 | S 1/2 | 9.375 | - | - | - | - |
| 19.41 | 0.764 | 60.98 | 2.4 | S 3/4 | 9.5 | 19.5 | - | - | 19 |
| 19.51 | 0.768 | 61.29 | 2.41 | T | 9.625 | - | 61.5 | 21.5 | - |
| 19.62 | 0.772 | 61.64 | 2.43 | T 1/4 | 9.75 | - | - | - | - |
| 19.84 | 0.781 | 62.33 | 2.45 | T 1/2 | 10 | 20 | - | - | 20 |
| 20.02 | 0.788 | 62.89 | 2.48 | U | 10.25 | - | 62.75 | 22.75 | 21 |
| 20.2 | 0.797 | 63.46 | 2.5 | U 1/2 | 10.5 | 20.25 | - | - | 22 |
| 20.32 | 0.8 | 63.84 | 2.51 | V | 10.625 | - | 63 | 23.75 | - |
| 20.44 | 0.805 | 64.21 | 2.53 | V 1/4 | 10.75 | - | - | - | - |
| 20.68 | 0.814 | 64.97 | 2.56 | V 1/2 | 11 | 20.75 | - | - | 23 |
| 20.76 | 0.817 | 65.22 | 2.57 | W | 11.125 | - | 65 | 25 | - |
| 20.85 | 0.821 | 65.5 | 2.58 | W 1/4 | 11.25 | - | - | - | - |
| 20.94 | 0.824 | 65.78 | 2.59 | W 1/2 | 11.375 | - | - | - | - |
| 21.08 | 0.83 | 66.22 | 2.61 | W 3/4 | 11.5 | 21 | - | - | 24 |
| 21.18 | 0.834 | 66.54 | 2.62 | X | 11.625 | - | 66.25 | 26.25 | - |
| 21.24 | 0.836 | 66.73 | 2.63 | X 1/4 | 11.75 | - | - | - | - |
| 21.3 | 0.839 | 66.92 | 2.64 | X 1/2 | 11.875 | - | - | - | - |
| 21.49 | 0.846 | 67.51 | 2.66 | Y | 12 | 21.25 | 67.5 | 27.5 | 25 |
| 21.69 | 0.854 | 68.14 | 2.68 | Y 1/2 | 12.25 | - | - | - | - |
| 21.89 | 0.862 | 68.77 | 2.71 | Z | 12.5 | 21.75 | 68.75 | 28.75 | 26 |
| 22.1 | 0.87 | 69.43 | 2.73 | Z +1/2 | 12.75 | - | - | - | - |
| 22.33 | 0.879 | 70.15 | 2.76 | Z+1 | 13 | 22 | - | - | 27 |
| 22.6 | 0.89 | 71 | 2.8 | Z+1.5 | 13.5 | - | - | - | - |
| 22.69 | 0.893 | 71.28 | 2.81 | Z+2 | - | - | - | - | - |
| 22.92 | 0.902 | 72 | 2.83 | Z+2.5 | - | - | - | - | - |
| 23.06 | 0.908 | 72.45 | 2.85 | Z+3 | - | - | - | - | - |
| 23.24 | 0.915 | 73.01 | 2.87 | Z+3.5 | - | - | - | - | - |
| 23.47 | 0.924 | 73.73 | 2.9 | Z+4 | - | - | - | - | - |
| 23.55 | 0.927 | 73.98 | 2.91 | Z+4.5 | - | - | - | - | - |
| 23.87 | 0.94 | 74.99 | 2.95 | Z+5 | - | - | - | - | - |
| 24.27 | 0.956 | 76.25 | 3 | Z+6 | - | - | - | - | - |