Complete 2026 universal ring size conversion chart โ UK, US, EU (ISO), French, Japanese, Swiss and Chinese ring sizes in one table. Full UK AโZ+4 chart with diameter and circumference in MM and CM, women's and men's averages, free calculator and expert conversion guide.
Uses sequential letters A through Z+4 (54 half sizes). Each half-step = approx 0.4mm circumference. The UK system is used in the United Kingdom, Ireland, Australia, New Zealand and South Africa. Standard: BS EN 28653 / ISO 8653.
Uses numbers from ยฝ to 14 in quarter-size increments. There is no universal US standard โ sizes can vary slightly between jewellers. The US system is widely used across North and South America.
The most logical system โ the EU size number equals the inner circumference in millimetres directly. EU 51 = 51mm inner circumference. Standard: ISO 8653:2016. Used across most of continental Europe.
Uses numbers 1 to 34. The French size is approximately EU size minus 40 (e.g. EU 51 = French 11). Used in France, Belgium, Portugal and French-speaking countries. Closely related to the Swiss system.
Uses numbers 1 to 33 (JIS B 4516). The Japanese system is very similar to the Chinese system โ both are widely used across East and Southeast Asia. Japanese sizes run approximately 1โ2 sizes smaller than US for the same finger circumference.
The Swiss system (numbers 1โ33) is essentially identical to the French system and used in Switzerland, Austria and by luxury watch/jewellery brands. The Chinese system (GB/T standard, numbers 4โ33) closely mirrors the Japanese system and is used across China, Hong Kong and Macau.
Fingers are at their natural everyday size between 2pm and 5pm at room temperature (18โ22ยฐC). Avoid measuring first thing in the morning or after exercise โ this can shift your reading by 1โ2 sizes in any system.
Cut a strip about 6โ8mm wide and 12โ14cm long from thin printer paper. Clean straight edges are important โ any ragged edges add false width to the measurement. A soft sewing tape measure also works well.
Wrap snugly around the base of the specific finger you will wear the ring on. Mark the overlap point precisely. The dominant hand is typically 0.5โ1 UK size (0.4mm circumference) larger than the other hand.
Lay the strip against a ruler. Read the circumference in mm. This single value converts to any ring system in the world โ enter it into the calculator above using "Circumference in MM" to get all 7 system sizes instantly.
If you have an existing ring that fits, measure the inner diameter across the widest point with a ruler in mm. Divide by ฯ (3.1416) to get circumference, or simply enter the diameter value directly into the calculator above.
Take 3 readings across the day. Use the largest as your ring size. If your measurement falls between two sizes in any system, always choose the larger one โ a slightly loose ring is always safer and more comfortable.
| ๐ฌ๐ง UK | ๐ Diam MM | ๐ Diam CM | โญ Circ MM | โญ Circ CM | ๐ Diam Inch | โญ Circ Inch | ๐บ๐ธ US | ๐ฉ๐ช EU | ๐ซ๐ท French | ๐ฏ๐ต Japan | ๐จ๐ญ Swiss | ๐จ๐ณ Chinese | Category |
|---|