Ring Size Converter
Convert ring sizes between US, UK, EU, Japan and inner diameter (mm) — perfect for buying rings from overseas jewellers.
Measure finger (circumference mm)
Printable sizer temporarily unavailable while its circumference scale and 50 mm calibration bar are rebuilt.
Wide bands may need about 0.5–1 US size larger. Reference points retain the ISO 8653 relationship where represented; regional and brand mappings are nearest matches.
Shoe sizes: shoe size converter.
Convert ring sizes
Compare nearest regional markings and use measured circumference as a starting point before confirming fit with a jeweller.
FAQ
How accurate is this?
Cross-system results are nearest matches, not exact equivalents. Measure more than once and confirm with the jeweller, especially for expensive, non-resizable or unusually shaped rings.
Which systems are covered?
US, UK, EU, inner diameter (mm) and Japan (JP).
Can I measure my finger?
Wrap a strip around your finger, mark the overlap, measure length in mm, divide by π for inner diameter.
Do wide rings need a different size?
Often yes. A wide band may need about 0.5–1 US size larger than a narrow band, but the jeweller and ring design should decide the final fit.
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