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Ring size chart
US, UK, EU and Japanese ring sizes side by side, with inner diameter and circumference in millimetres.
Full ring size chart
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| US | UK | EU (ISO) | Japan | Diameter mm | Circumference mm |
|---|---|---|---|---|---|
| 3 | F | 44 | 4 | 14.1 | 44.2 |
| 3½ | G | 45 | — | 14.5 | 45.5 |
| 4 | H | 47 | 7 | 14.9 | 46.8 |
| 4½ | I | 48 | 8 | 15.3 | 48.0 |
| 5 | J½ | 49 | 9 | 15.7 | 49.3 |
| 5½ | K½ | 51 | 10 | 16.1 | 50.6 |
| 6 | L½ | 52 | 11 | 16.5 | 51.9 |
| 6½ | M½ | 53 | 13 | 16.9 | 53.1 |
| 7 | N½ | 54 | 14 | 17.3 | 54.4 |
| 7½ | O½ | 56 | 15 | 17.7 | 55.7 |
| 8 | P½ | 57 | 16 | 18.1 | 57.0 |
| 8½ | Q¼ | 58 | 17 | 18.5 | 58.2 |
| 9 | R½ | 60 | 18 | 18.9 | 59.5 |
| 9½ | S½ | 61 | 19 | 19.4 | 60.8 |
| 10 | T½ | 62 | 20 | 19.8 | 62.1 |
| 10½ | U½ | 63 | 22 | 20.2 | 63.3 |
| 11 | V½ | 65 | 23 | 20.6 | 64.6 |
| 11½ | W½ | 66 | 24 | 21.0 | 65.9 |
| 12 | X½ | 67 | 25 | 21.4 | 67.2 |
| 12½ | Y½ | 68 | 26 | 21.8 | 68.5 |
| 13 | Z½ (approx.) | 70 | 27 | 22.2 | 69.7 |
“Women” shows US 3–9 and “Men” US 8–13. These are just filters to shorten the table; anyone can wear any size. Japan: “—” means there is no matching Japanese size.
How to read the chart
Find the inner diameter of a ring that fits, or the circumference of the finger, in the last two columns. The same row gives the size in each system. If you fall between two rows, choose the larger size.
FAQ
Is there a "normal" ring size?
There is no official survey of ring sizes, so we do not give an average. Finger size varies a lot from person to person, even between the two hands of the same person. Measure the actual finger instead of guessing from an average.
Is EU the same as ISO?
Yes. The EU size is the inner circumference in millimetres, as ISO 8653 defines it, so EU 54 is 54 mm around the inside.
Why do charts differ slightly?
The US and UK systems were made in inches and letters, and metric sizes are rounded. Different charts round these numbers slightly differently.
Sources
How we calculate: the EU size is the inner circumference in millimetres, as defined in ISO 8653:2016. US sizes follow the US scale where each whole size adds 0.032 in (0.8128 mm) to the inner diameter, so diameter = 11.63 mm + 0.8128 mm × US size. UK letters follow British Standard 6820:1987 (size C = 40 mm circumference, each letter adds 1.25 mm). Japanese sizes come from the equivalency table on Wikipedia (Japanese sizes are whole numbers that do not follow a straight formula, so they are rounded to the nearest size). Sources: ISO 8653:2016, Ring size (Wikipedia), equivalency table, Larson Jewelers conversion chart. Charts from different jewelers can round slightly differently, so for an important ring check with the jeweler.
Find your size on screen
Calibrate with a bank card, lay a ring on the screen and read the size in four systems.
Find your size on screen