* Ring size conversion
UK K½ ring size conversion
UK K½ is an inside diameter of 16 mm (circumference 50.3 mm). In other systems that is US 5.5 = UK K½ = EU 50 = Japan 9.
Published July 11, 2026
UK K½ — full conversion
- Inside diameter
- 16 mm
- Inside circumference
- 50.3 mm
- Japan
- 9
- US / Canada
- 5.5
- UK / Australia
- K½
- EU (ISO)
- 50
Nearby sizes
- Ø 15.6 mm — US 5 = UK J½ = EU 49 = Japan 8
- Ø 16.4 mm — US 6 = UK L½ = EU 51 = Japan 10
Buying tips for UK K½
- 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 UK K½ in other ring size systems?
- A. UK K½ converts to US 5.5 = UK K½ = EU 50 = Japan 9.
- Q. What is the diameter of UK K½?
- A. Inside diameter 16 mm; inside circumference 50.3 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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