Ring Size Calculator
From Circumference
mm
From Diameter
mm
Formula
US size ≈ (circumference mm − 36.5) / 2.55 | EU size ≈ circumference mm
Frequently Asked Questions
How do I measure my ring size at home?
Wrap a thin strip of paper around your finger, mark where it overlaps, and measure the length in mm. That is your circumference. Alternatively, measure the inner diameter of a ring that fits well.
What is the most common ring size?
The most common women's ring size is US 6 (circumference ~52mm). The most common men's ring size is US 10 (circumference ~62.1mm).
Do US and EU ring sizes differ?
Yes. EU sizes are based on the inner circumference in mm (e.g., EU 52). US sizes use a numbered scale (e.g., US 6 ≈ EU 52).