Convert a ring’s inside circumference, inside diameter and ISO designation. SizeRoute does not claim unsupported US, UK, EU or Japan mappings.
How it works: Measure the widest inside diameter of a well-fitting ring or use a professional ring gauge for an important purchase.
Source Basis: ISO 8653:2016 and the mathematical relationship between a circle’s diameter and circumference. Confidence Level: Diameter-to-circumference geometry has high confidence; the ISO designation follows the reviewed circumference basis.
| System | Size / value | System | Size / value |
|---|
Swipe to see all columns →