To convert a ring size between countries, match the inside circumference in millimeters. A US size 7 is a UK size N½, a European size 54, a Japanese size 14 and an Indian size 14, and all of them measure about 54.4 mm around the inside. The full chart below converts every US size from 3 to 13, in half sizes, into UK, EU, Japanese and Indian sizes.
Use this page when you buy a ring from another country, order a gift for someone abroad, or need to read a size written in a system you do not know.
International Ring Size Conversion Chart
Each row is one ring size. Read across to find the same size in another country.
| US and Canada | UK and Australia | EU (ISO) | Japan | India | Diameter (mm) | Around (mm) |
|---|---|---|---|---|---|---|
| 3 | F½ | 44 | 4 | 4 | 14.1 | 44.2 |
| 3.5 | G½ | 45 | 5 | 6 | 14.5 | 45.5 |
| 4 | H½ | 47 | 7 | 7 | 14.9 | 46.8 |
| 4.5 | I½ | 48 | 8 | 8 | 15.3 | 48.0 |
| 5 | J½ | 49 | 9 | 9 | 15.7 | 49.3 |
| 5.5 | K½ | 51 | 10 | 11 | 16.1 | 50.6 |
| 6 | L½ | 52 | 12 | 12 | 16.5 | 51.9 |
| 6.5 | M½ | 53 | 13 | 13 | 16.9 | 53.1 |
| 7 | N½ | 54 | 14 | 14 | 17.3 | 54.4 |
| 7.5 | O½ | 56 | 15 | 16 | 17.7 | 55.7 |
| 8 | P½ | 57 | 16 | 17 | 18.1 | 57.0 |
| 8.5 | Q½ | 58 | 17 | 18 | 18.5 | 58.2 |
| 9 | R½ | 60 | 18 | 19 | 18.9 | 59.5 |
| 9.5 | S½ | 61 | 19 | 21 | 19.4 | 60.8 |
| 10 | T½ | 62 | 20 | 22 | 19.8 | 62.1 |
| 10.5 | U½ | 63 | 22 | 23 | 20.2 | 63.3 |
| 11 | V½ | 65 | 23 | 25 | 20.6 | 64.6 |
| 11.5 | W½ | 66 | 24 | 26 | 21.0 | 65.9 |
| 12 | X½ | 67 | 25 | 27 | 21.4 | 67.2 |
| 12.5 | Z | 68 | 26 | 28 | 21.8 | 68.5 |
| 13 | Z+1 | 70 | 27 | 30 | 22.2 | 69.7 |
Diameters follow the standard US scale, where each full size adds about 0.81 mm. Japanese sizes follow the International Gem Society ring size comparison chart, and Indian sizes are matched by circumference to the Tanishq ring size guide. Brands round sizes slightly differently, so treat any single row as a close match, not an exact one.
How to Use This Chart
- Find your size in a system you know. If you only know your measurement, use the diameter or circumference columns.
- Read across the row to the country you are buying from.
- Check the seller’s own chart and compare in millimeters, because that is the one number every chart shares.
- If you fall between two sizes, choose the larger one. A ring that is slightly big is easier to fix than one that will not pass your knuckle.
Do not know your size yet? Our free ring size chart calculator turns a measurement into all of these sizes at once.
How Each Ring Size System Works
United States and Canada
The US and Canada use numbers, usually from 3 to 13, with half and quarter sizes. Each full size adds about 0.81 mm to the inside diameter and about 2.55 mm to the circumference.
UK, Ireland, Australia and New Zealand
These countries use letters from A to Z, with half sizes written as ½, such as Q½. Sizes above Z continue as Z+1, Z+2 and so on. For a worked example, see what a size 8 ring is in the UK, and for larger men’s sizes, what letter a size 10 men’s ring is.
Europe (ISO)
Most of Europe follows the international standard ISO 8653, where the ring size is simply the inside circumference in millimeters. A ring that measures 54 mm around is a size 54. This makes the European system the easiest to check with a tape measure. Italy, Spain and Switzerland often use the same circumference minus 40, so a European 54 becomes a 14.
Japan and China
Japan and China use numbers, typically from 1 to 30. Each step is about 1 mm of circumference, but the numbers do not follow a simple formula, so always use a chart.
India
Indian jewelers also use numbers, usually from 1 to 30. In practice an Indian size is close to the inside circumference minus 40 mm, so a 54.4 mm ring is about Indian size 14. Indian and Japanese numbers are often the same or one apart for common sizes.
Quick Conversions People Search For
| Question | Answer |
|---|---|
| US 6 in UK size | L½ |
| US 7 in EU size | 54 |
| US 8 in UK size | P½ |
| UK M½ in US size | 6½ |
| EU 52 in US size | 6 |
| Indian size 12 in US size | 6 |
| Japanese size 9 in US size | 5 |
| US 10 in Indian size | 22 |
How to Measure Your Size Before You Convert
- Measure a ring you own: measure straight across the inside in millimeters and find the closest diameter in the chart.
- Measure your finger: wrap a soft tape or a paper strip around the base of the finger and read the length. Our guide to measuring ring size with a fabric tape measure shows how.
- Print a sizer: download our free sizer from the printable ring sizer guide, which lists US and UK sizes together.
Measure at the end of the day and at room temperature, and measure two or three times. Most women wear between US 5 and 7. See the average female ring size guide for more.
Tips for Buying a Ring From Another Country
- Compare in millimeters, not just size names. It removes most conversion errors.
- Size up for wide bands. Bands of 6 mm or more feel tighter, so you may need a quarter to half size larger.
- Check the return and resizing policy, because sending a ring back across borders can be slow and costly.
- Watch out for half sizes. Some systems have half sizes and others do not, so a US 7.5 may land between two sizes in another chart.
Frequently Asked Questions
How do I convert US ring size to UK?
Find the US size in the chart and read the UK letter in the same row. For example, US 6 is UK L½, US 7 is UK N½ and US 8 is UK P½.
Is European ring size the same as circumference?
Yes. Under the ISO standard, the European size is the inside circumference in millimeters, so size 52 measures 52 mm around.
What is a size 7 ring in Indian size?
A US size 7 is about Indian size 14, with an inside circumference of about 54.4 mm.
Are Japanese and Chinese ring sizes the same?
Yes, they generally use the same numbered scale. A US 6 is about size 12 in both.
Are men’s and women’s ring sizes converted differently?
No. A size measures the same whoever wears it. Men simply tend to wear larger sizes.
What should I do if I am between two sizes?
Choose the larger size, especially for wide bands, and check whether the ring can be resized later.
Final Thoughts
Every ring size system measures the same thing: the inside of the ring. When you convert, match the millimeters first and the size name second. Use the chart above, check the seller’s own chart, and when in doubt, size up slightly.
