Online Ring Sizer
Ring Size Chart
Inside diameter measures across a ring's inner opening; circumference measures around it or your finger. Measurements are in millimetres. Regional equivalents are approximate.
Scroll for more sizes; swipe sideways for more columns. US sizes stay visible. Keyboard: focus the chart and use the arrow keys.
| US / Canada | Inside diameter (mm) | Inside circumference (mm) | UK / Australia | EU / ISO (approx.) | Japan / Asia |
|---|---|---|---|---|---|
| 3 | 14.1 | 44.30 | F | 44 | 4 |
| 3¼ | 14.3 | 44.92 | F½ | 45 | 5 |
| 3½ | 14.5 | 45.55 | G | 46 | Not listed |
| 3¾ | 14.7 | 46.18 | G½ | 46 | 6 |
| 4 | 14.9 | 46.81 | H | 47 | 7 |
| 4¼ | 15.1 | 47.44 | H½ | 47 | Not listed |
| 4½ | 15.3 | 48.07 | I | 48 | 8 |
| 4¾ | 15.5 | 48.69 | I½ | 49 | Not listed |
| 5 | 15.7 | 49.32 | J | 49 | 9 |
| 5¼ | 15.9 | 49.95 | J½ | 50 | Not listed |
| 5½ | 16.1 | 50.58 | K | 51 | 10 |
| 5¾ | 16.3 | 51.21 | K½ | 51 | Not listed |
| 6 | 16.5 | 51.84 | L | 52 | 11 |
| 6¼ | 16.7 | 52.46 | L½ | 52 | 12 |
| 6½ | 16.9 | 53.09 | M | 53 | 13 |
| 6¾ | 17.1 | 53.72 | M½ | 54 | Not listed |
| 7 | 17.3 | 54.35 | N | 54 | 14 |
| 7¼ | 17.5 | 54.98 | N½ | 55 | Not listed |
| 7½ | 17.7 | 55.61 | O | 56 | 15 |
| 7¾ | 17.9 | 56.23 | O½ | 56 | Not listed |
| 8 | 18.1 | 56.86 | P | 57 | 16 |
| 8¼ | 18.3 | 57.49 | P½ | 57 | Not listed |
| 8½ | 18.5 | 58.12 | Q | 58 | 17 |
| 8¾ | 18.8 | 59.06 | Q½ | 59 | Not listed |
| 9 | 19.0 | 59.69 | R | 60 | 18 |
| 9¼ | 19.2 | 60.32 | R½ | 60 | Not listed |
| 9½ | 19.4 | 60.95 | S | 61 | 19 |
| 9¾ | 19.6 | 61.58 | S½ | 62 | Not listed |
| 10 | 19.8 | 62.20 | T | 62 | 20 |
| 10¼ | 20.0 | 62.83 | T½ | 63 | 21 |
| 10½ | 20.2 | 63.46 | U | 63 | 22 |
| 10¾ | 20.4 | 64.09 | U½ | 64 | Not listed |
| 11 | 20.6 | 64.72 | V | 65 | 23 |
| 11¼ | 20.8 | 65.35 | V½ | 65 | Not listed |
| 11½ | 21.0 | 65.97 | W | 66 | 24 |
| 11¾ | 21.2 | 66.60 | W½ | 67 | Not listed |
| 12 | 21.4 | 67.23 | X | 67 | 25 |
| 12¼ | 21.6 | 67.86 | X½ | 68 | Not listed |
| 12½ | 21.8 | 68.49 | Y | 68 | 26 |
| 12¾ | 22.0 | 69.12 | Z | 69 | Not listed |
| 13 | 22.2 | 69.74 | Z½ | 70 | 27 |
| 13¼ | 22.4 | 70.37 | Not listed | 70 | Not listed |
| 13½ | 22.6 | 71.00 | Z1 | 71 | Not listed |
Reading the chart
Retailer charts can vary. “Not listed” means the source has no equivalent label. Quarter US sizes and half UK letters are included where listed. EU / ISO is circumference rounded to the nearest millimetre, so the same EU label can appear on more than one row.
Diameter follows the GIA reference chart. Circumference is calculated as π × diameter and displayed to two decimal places; this display precision does not imply measurement accuracy.
Source: GIA International Ring Size Chart · gia-v1 · last verified . View sources and conversion rules.
Frequently Asked Questions
What is the average ring size for women and men?
The most common ring sizes for women are US 6 to 7 (UK L to N, EU 52 to 54). For men, the average ring size is US 9 to 10 (UK R to T, EU 60 to 62). However, every finger is unique and measuring beforehand is always recommended.
How do US, UK, and European ring sizes compare?
The United States and Canada use numerical sizes from 3 to 13.5 based on inside diameter. The United Kingdom, Australia, and South Africa use alphabetical letters from A to Z based on inside circumference. The European Union and ISO 8653 standard represent ring sizes directly by inner circumference in millimeters (e.g., EU 54 = 54.0 mm circumference).
Which measurement is the most reliable when ordering jewelry online?
Inside diameter in millimeters (mm) is the universal engineering standard. Millimeter measurements do not change across regions, whereas letter or numerical labels can have slight variance between jewelers.