Ring Size Calculator
Convert between international ring sizes and physical measurements.
Conversion Results
How Ring Sizing Works
Ring sizes are based on either the inside diameter or inside circumference of a ring. Different regions use different naming conventions:
- US & Canada: Numeric sizes (e.g., 6, 6.5, 7) that scale by diameter.
- UK & Australia: Alphabetical sizes (e.g., L, M, N) including half-sizes (N ½).
- Europe: Directly maps to the inside circumference in millimeters (e.g., EU 54 is ~54mm circumference).
- India: Numeric sizes typically ranging from 1 to 30.
- Japan: Numeric sizes (e.g., 11, 12, 13) that are different from the US standard.
If you measure your finger with string or paper, you are finding the Circumference. If you measure an existing ring straight across the inside, you are finding the Diameter.