Ring Size Converter
Select your known ring size in any system and instantly see the equivalent in all other international sizing standards.
Your ring size in all systems
US
5
UK
J
EU
49
Japanese
9
Diameter
15.7 mm
Circumference
49.3 mm
How Ring Size Conversion Works
Ring sizes are based on the inner circumference or diameter of the ring band. Different countries developed their own numbering systems, but they all measure the same physical property. Our converter maps between these systems using standardized measurements.
The most universal measurement is the inner diameter in millimeters. If you can measure the inner diameter of an existing ring, you can find your size in any system using our converter above.
Common Conversions
Women's Average
US 6 = UK L = EU 51 = JP 12
16.5 mm diameter
Men's Average
US 10 = UK T = EU 62 = JP 21
19.8 mm diameter
Important Notes
- •Conversions are approximate. Manufacturing tolerances mean slight variations between brands.
- •When a size falls between two values in another system, we show the nearest standard size.
- •For the most accurate fit, always try to get sized at a local jeweler.