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* Ring size conversion

EU 64 ring size conversion

EU 64 is an inside diameter of 20.4 mm (circumference 64.1 mm). In other systems that is US 11 = UK V½ = EU 64 = Japan 20.

Published July 11, 2026

EU 64 — full conversion

Inside diameter
20.4 mm
Inside circumference
64.1 mm
Japan
20
US / Canada
11
UK / Australia
EU (ISO)
64

Nearby sizes

  • Ø 20 mm — US 10.5 = UK U½ = EU 63 = Japan 19
  • Ø 20.8 mm — US 11.5 = UK W½ = EU 65 = Japan 21

Buying tips for EU 64

  • Wide bands feel tighter — consider going up ~½ US size for bands over 6 mm.
  • Printable paper sizers are often ¼–½ size off; prefer a metal gauge at a jeweler.
  • Selling the ring for gold? Check 18K ring melt value or the karat × weight calculator.

* Frequently asked

FAQ

Q. What is EU 64 in other ring size systems?
A. EU 64 converts to US 11 = UK V½ = EU 64 = Japan 20.
Q. What is the diameter of EU 64?
A. Inside diameter 20.4 mm; inside circumference 64.1 mm.
Q. How should I measure my finger?
A. Measure at the end of the day when fingers are warm. The ring must clear the knuckle; if knuckle and base differ, size for the knuckle and consider a comfort-fit band.
Q. Can every ring be resized to this size?
A. Most gold and platinum bands can move 1–2 sizes. Tension settings, eternity bands, and some titanium/tungsten rings cannot. See a jeweler before ordering a resize.

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