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Ring size chart: international sizes in mm and inches
Every US quarter size from 3 to 16 with its UK, European, Japanese, Indian and Swiss equivalent, plus the inside diameter and circumference in millimetres and inches.
| US / CA | UK / AU | EU / ISO | JP / CN | India | IT / ES / CH | Diameter mm | Circ. mm | Diameter in |
|---|---|---|---|---|---|---|---|---|
| 3 | F½ | 44 | 4 | 4 | 4 | 14.1 | 44.2 | 0.554 |
| 3¼ | G | 45 | 5 | 5 | 5 | 14.3 | 44.8 | 0.562 |
| 3½ | G½ | 45 | 5 | 5 | 5 | 14.5 | 45.5 | 0.570 |
| 3¾ | H | 46 | 6 | 6 | 6 | 14.7 | 46.1 | 0.578 |
| 4 | H½ | 47 | 7 | 6 | 7 | 14.9 | 46.8 | 0.586 |
| 4¼ | I | 47 | 8 | 7 | 7 | 15.1 | 47.4 | 0.594 |
| 4½ | I½ | 48 | 8 | 8 | 8 | 15.3 | 48.0 | 0.602 |
| 4¾ | J | 49 | 8 | 9 | 9 | 15.5 | 48.7 | 0.610 |
| 5 | J½ | 49 | 9 | 9 | 9 | 15.7 | 49.3 | 0.618 |
| 5¼ | K | 50 | 10 | 10 | 10 | 15.9 | 49.9 | 0.626 |
| 5½ | K½ | 51 | 10 | 11 | 11 | 16.1 | 50.6 | 0.634 |
| 5¾ | L | 51 | 10 | 11 | 11 | 16.3 | 51.2 | 0.642 |
| 6 | L½ | 52 | 11 | 12 | 12 | 16.5 | 51.9 | 0.650 |
| 6¼ | M | 52 | 12 | 13 | 12 | 16.7 | 52.5 | 0.658 |
| 6½ | M½ | 53 | 13 | 13 | 13 | 16.9 | 53.1 | 0.666 |
| 6¾ | N | 54 | 13 | 13 | 14 | 17.1 | 53.8 | 0.674 |
| 7 | N½ | 54 | 14 | 14 | 14 | 17.3 | 54.4 | 0.682 |
| 7¼ | O | 55 | 14 | 15 | 15 | 17.5 | 55.0 | 0.690 |
| 7½ | O½ | 56 | 15 | 15 | 16 | 17.7 | 55.7 | 0.698 |
| 7¾ | P | 56 | 16 | 16 | 16 | 17.9 | 56.3 | 0.706 |
| 8 | P½ | 57 | 16 | 17 | 17 | 18.1 | 57.0 | 0.714 |
| 8¼ | Q | 58 | 16 | 17 | 18 | 18.3 | 57.6 | 0.722 |
| 8½ | Q½ | 58 | 17 | 18 | 18 | 18.5 | 58.2 | 0.730 |
| 8¾ | R | 59 | 17 | 19 | 19 | 18.7 | 58.9 | 0.738 |
| 9 | R½ | 60 | 18 | 19 | 20 | 18.9 | 59.5 | 0.746 |
| 9¼ | S | 60 | 19 | 20 | 20 | 19.1 | 60.2 | 0.754 |
| 9½ | S½ | 61 | 19 | 21 | 21 | 19.4 | 60.8 | 0.762 |
| 9¾ | T | 61 | 19 | 21 | 21 | 19.6 | 61.4 | 0.770 |
| 10 | T½ | 62 | 20 | 22 | 22 | 19.8 | 62.1 | 0.778 |
| 10¼ | U | 63 | 21 | 23 | 23 | 20.0 | 62.7 | 0.786 |
| 10½ | U½ | 63 | 22 | 23 | 23 | 20.2 | 63.3 | 0.794 |
| 10¾ | V | 64 | 23 | 24 | 24 | 20.4 | 64.0 | 0.802 |
| 11 | V½ | 65 | 23 | 25 | 25 | 20.6 | 64.6 | 0.810 |
| 11¼ | W | 65 | 24 | 26 | 25 | 20.8 | 65.3 | 0.818 |
| 11½ | W½ | 66 | 24 | 26 | 26 | 21.0 | 65.9 | 0.826 |
| 11¾ | X | 67 | 24 | 26 | 27 | 21.2 | 66.5 | 0.834 |
| 12 | X½ | 67 | 25 | 27 | 27 | 21.4 | 67.2 | 0.842 |
| 12¼ | Y½ | 68 | 25 | 28 | 28 | 21.6 | 67.8 | 0.850 |
| 12½ | Z | 68 | 26 | 28 | 28 | 21.8 | 68.5 | 0.858 |
| 12¾ | Z | 69 | 27 | 29 | 29 | 22.0 | 69.1 | 0.866 |
| 13 | Z+1 | 70 | 27 | 30 | 30 | 22.2 | 69.7 | 0.874 |
| 13¼ | Z+1 | 70 | 27 | 30 | 30 | 22.4 | 70.4 | 0.882 |
| 13½ | Z+2 | 71 | 27 | 31 | 31 | 22.6 | 71.0 | 0.890 |
| 13¾ | Z+2 | 72 | — | 32 | 32 | 22.8 | 71.6 | 0.898 |
| 14 | Z+3 | 72 | — | 32 | 32 | 23.0 | 72.3 | 0.906 |
| 14¼ | Z+3 | 73 | — | 33 | 33 | 23.2 | 72.9 | 0.914 |
| 14½ | Z+4 | 74 | — | 33 | 34 | 23.4 | 73.6 | 0.922 |
| 14¾ | Z+4 | 74 | — | 34 | 34 | 23.6 | 74.2 | 0.930 |
| 15 | Z+5 | 75 | — | 35 | 35 | 23.8 | 74.8 | 0.938 |
| 15¼ | Z+5 | 75 | — | 35 | 35 | 24.0 | 75.5 | 0.946 |
| 15½ | Z+6 | 76 | — | 36 | 36 | 24.2 | 76.1 | 0.954 |
| 15¾ | Z+6 | 77 | — | 36 | 37 | 24.4 | 76.8 | 0.962 |
| 16 | Z+7 | 77 | — | 37 | 37 | 24.6 | 77.4 | 0.970 |
"—" means that system has no standard size at that exact point; use the nearest row. Japanese sizes are also used in China and South Korea.
Where each system is used
- US & Canada: United States, Canada, Mexico.
- UK & Australia: UK, Ireland, Australia, New Zealand, South Africa.
- EU / ISO: France, Germany, Nordics, most of continental Europe (ISO 8653).
- Japan & China: Japan, China, South Korea.
- India: India.
- Italy, Spain, Swiss: Italy, Spain, Switzerland, Netherlands.
How this chart was built
Diameters come from the US scale definition: size 0 is 0.458 inch (11.63 mm) inside diameter and each whole size adds 0.032 inch (0.8128 mm). Circumference is diameter × π. EU sizes follow ISO 8653:2016 (circumference in mm, rounded), UK letters follow BS 6820:1987 (size C = 40 mm, each letter +1.25 mm), and Italy, Spain and Switzerland use circumference minus 40. Japanese and Indian columns come from the standard equivalency table and were cross-checked against a Japanese retailer's published chart. Brands differ by up to half a size, so if a retailer publishes its own chart, trust theirs for that purchase.
Actual-size ring size chart
Numbers on a screen are not actual size. To compare a ring against real circles, calibrate the online ring sizer with a bank card first, or print the printable sizer at 100% scale.
Questions people ask
What does the EU ring size number mean?
Under ISO 8653, used across continental Europe, the size number is the inside circumference of the ring in millimetres. An EU 54 ring measures 54 mm around the inside, which is about a US 7.
What is ring size 7 in mm?
A US size 7 has an inside diameter of 17.3 mm and an inside circumference of 54.4 mm. That is UK N½, EU 54 and Japanese 14.
Why do Japanese and Chinese ring sizes skip numbers?
The East Asian scale is numeric but not linear, so its steps do not line up one-to-one with US quarter sizes. Some US quarter sizes share a Japanese size and others have none. The chart shows the nearest standard equivalent.
Is the chart printable at actual size?
The table prints cleanly, but a table cannot size a finger. For a physical tool use the printable ring sizer and check its 50 mm ruler after printing at 100% scale.