* Ring size conversion
JP 19 ring size conversion
JP 19 is an inside diameter of 20 mm (circumference 62.8 mm). In other systems that is US 10.5 = UK U½ = EU 63 = Japan 19.
Published July 11, 2026
JP 19 — full conversion
- Inside diameter
- 20 mm
- Inside circumference
- 62.8 mm
- Japan
- 19
- US / Canada
- 10.5
- UK / Australia
- U½
- EU (ISO)
- 63
Nearby sizes
- Ø 19.6 mm — US 10 = UK T½ = EU 62 = Japan 18
- Ø 20.4 mm — US 11 = UK V½ = EU 64 = Japan 20
Buying tips for JP 19
- 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 JP 19 in other ring size systems?
- A. JP 19 converts to US 10.5 = UK U½ = EU 63 = Japan 19.
- Q. What is the diameter of JP 19?
- A. Inside diameter 20 mm; inside circumference 62.8 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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