| US/Canada | UK/Australia | EU | Japan | Diameter (mm) | Circ. (mm) |
|---|---|---|---|---|---|
| 3 | F | 44 | 4 | 14.1 | 44.2 |
| 3.5 | G | 45.5 | 5 | 14.3 | 44.8 |
| 4 | H | 46.5 | 7 | 14.9 | 46.8 |
| 4.5 | I | 47.75 | 8 | 15.3 | 48.0 |
| 5 | J | 49 | 9 | 15.7 | 49.3 |
| 5.5 | K | 50.25 | 10 | 16.0 | 50.3 |
| 6 | L | 51.5 | 11 | 16.5 | 51.9 |
| 6.5 | M | 52.75 | 12 | 16.9 | 53.1 |
| 7 | N | 54 | 13 | 17.3 | 54.4 |
| 7.5 | O | 55.25 | 14 | 17.7 | 55.7 |
| 8 | P | 56.5 | 15 | 18.1 | 56.9 |
| 8.5 | Q | 57.75 | 16 | 18.5 | 58.2 |
| 9 | R | 59 | 18 | 18.9 | 59.5 |
| 9.5 | S | 60.25 | 19 | 19.4 | 60.8 |
| 10 | T | 61.5 | 20 | 19.8 | 62.1 |
| 10.5 | U | 62.75 | 22 | 20.2 | 63.4 |
| 11 | V | 64 | 23 | 20.6 | 64.6 |
| 11.5 | W | 65.25 | 24 | 21.0 | 65.9 |
| 12 | X | 66.5 | 25 | 21.4 | 67.2 |
| 12.5 | Y | 67.75 | 26 | 21.8 | 68.5 |
| 13 | Z | 69 | 27 | 22.2 | 69.7 |
How to Measure Your Ring Size
The string method is one of the easiest ways to find your ring size at home. Cut a thin strip of paper or a piece of non-stretchy string. Wrap it snugly around the base of the finger you want to measure -- make sure it can still slide over your knuckle. Mark where the end meets the rest of the strip, then lay it flat and measure the length in millimeters. This gives you the circumference. Compare it with the circumference column in the chart above to find your size. For best results, measure at the end of the day when your fingers are slightly larger, and measure several times to confirm consistency.
About Ring Size Conversion
Ring sizing systems vary around the world. The US and Canada use a numerical scale (typically 3-13 including half sizes). The UK and Australia use an alphabetical system (A-Z). European sizes correspond to the inner circumference in millimeters. Japan uses its own numerical system. The inner diameter and circumference measurements provide a universal reference that works regardless of regional sizing standards. When buying rings internationally, always verify the sizing system being used.
FAQ
Q: What is the most common ring size?
A: The most common ring size for women is US 6 to 7, while for men it is US 9 to 10. However, ring size varies greatly from person to person, so always measure before purchasing.
Q: How do I convert US ring size to UK ring size?
A: US and UK ring sizes use completely different systems -- US uses numbers while UK uses letters. For example, US 6 corresponds to UK L, and US 9 corresponds to UK R. Use the conversion chart above for accurate mapping between the two systems.
Q: Do ring sizes change with temperature or time of day?
A: Yes. Fingers tend to swell in warm weather and shrink in cold weather. They are also slightly larger at the end of the day. For the most accurate measurement, measure your finger at the end of the day at a comfortable room temperature.
Q: What if my ring size falls between two sizes?
A: If your measurement falls between two sizes, it is generally recommended to round up to the larger size, especially for wider bands. Wide-band rings tend to fit more tightly than thin-band rings of the same size.
Q: Can a jeweler resize a ring?
A: Most rings can be resized by a professional jeweler, typically up or down by 1-2 sizes. However, certain materials (tungsten, titanium, ceramic) and rings with stones set all around the band may be difficult or impossible to resize. Always check with a jeweler before purchasing if you are unsure of your size.