Ring Size Calculator
Ring Size Calculator converts finger measurements to ring sizes in US, UK, European and Japanese sizing. Enter circumference or diameter in mm and see your size across all systems instantly.
Última atualização: July 2026
A ring size calculator converts finger circumference or diameter to ring sizes across US, UK, EU and JP standards. Enter the measurement in mm or use a common reference object. All calculations run in your browser.
Wrap string around finger, measure length in mm.
🔒 All calculations run in your browser. Sizes are approximate — try on a physical ring for confirmation.
Como usar Ring Size Calculator
- Measure your finger circumference (mm) or diameter (mm).
- Read your ring size in US, UK, EU and JP sizing systems.
- Optionally use the ring diameter if you have an existing ring to measure.
Perguntas frequentes
How do I measure my finger?
Wrap a string or paper strip around your finger, mark where it meets, and measure the length in mm — that's your circumference.
What's the difference between sizing systems?
US/Canada uses numbers (5–13), UK/Australia uses letters (H–Z), EU uses circumference in mm (48–72), JP uses numbers (9–27).
Is my data stored?
No — all calculations run in your browser.
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