Ring Size Converter | International Ring Size Conversion

Ring Size Converter

Convert between international ring size systems: US, UK, EU, Japan, and more. Includes finger measurement guide.

Professional Jewelry Standard

Ring Type

Conversion Type

From System

Ring Size

(US)

Finger Diameter

mm

Inside diameter

Finger Circumference

mm

Finger measurement

Convert To System

Hand

Finger

Converted Ring Size

US 7 = UK O½ = EU 54 = Japan 13

Diameter: 17.3mm • Circumference: 54.5mm

Australia: O • Switzerland: 13.5 • Italy: 9