Ring Size Converter
Convert between US, UK, EU, and metric ring sizes. Find your size by measuring your finger.
| US | UK | EU | Circ (mm) | Diam (mm) |
|---|
Wrap a thin strip of paper or string around your finger where you want to wear the ring. Mark where it overlaps and measure the length.
- Measure at the end of the day when fingers are at their largest.
- Avoid measuring when hands are cold — fingers shrink in the cold.
- Measure the specific finger and hand you plan to wear the ring on.
- If between sizes, round up for comfort.
- Wide band rings (over 6mm) usually require going up half a size.
- Use a flexible tape measure or a strip of paper for the most accurate result.
How ring sizing systems differ globally
US & Canada use a numerical scale from 1 to 13+ in half and quarter increments. Size 7 (circumference ~54.4mm) is the most common women's size; size 10 (circumference ~62.1mm) is common for men.
UK, Ireland, Australia & New Zealand use an alphabetical system starting at A. Each letter corresponds to roughly a 1.25mm step in circumference. Half sizes are denoted with a "1/2" suffix (e.g., N 1/2).
Europe & Asia (EU/ISO) use the inner circumference in millimetres as the size. A US size 7 equals approximately EU 54. This is the most logical system as the number directly tells you the inner circumference.
Japan & China use a smaller numerical scale (Japanese 1–27) and circumference in mm respectively, which differ from European standards.
When ordering internationally, always confirm which sizing system the retailer uses and provide your circumference in mm to avoid ambiguity.