Ring Size Converter
Convert ring sizes between US/Canada, UK/Australia, EU, and inner diameter in millimeters using a standard conversion chart.
Converted Sizes
US / Canada
7
UK / Australia
14
EU
54
Diameter (mm)
17.3
How to Use the Ring Size Converter
Select the sizing system you know (US/Canada, UK/Australia, EU, or inner diameter in millimeters) and enter your size. The converter matches it against a standard ring-size conversion chart and shows the equivalent size in every other system at once.
Why Ring Sizes Don't Convert With a Simple Formula
Like shoe sizes, ring sizing systems were developed independently by different regions and don't scale in a simple linear way against each other. This tool uses a reference conversion table, matching your entered size to the closest row and reading across for the other systems, rather than a single formula.
Example
A US size 7 converts to approximately UK/Australia size N (14), EU size 54, and an inner diameter of about 17.3mm.
Common Use Cases
- Buying a ring from an international jeweler that lists sizes in a different system.
- Converting a measured ring diameter into a standard size to order.
- Checking a partner's or gift recipient's ring size across regions.
FAQs
How do I measure my ring size at home?
Measure the inner diameter of a ring that already fits well (in millimeters) using a ruler, or wrap a strip of paper or string around your finger and measure its circumference, then convert. Entering the diameter directly into the "Diameter (mm)" option above gives the most direct conversion.
Why does my converted size feel slightly off?
Standard conversion charts give a reliable starting point, but band width and finger shape can affect how a given size actually fits — a wider band typically fits more snugly than a thin band at the same listed size. When possible, get sized in person at a jeweler for the most accurate fit.
What if my exact size isn't in the table?
The converter matches your entered size to the closest available row in the reference chart, so sizes between listed increments will show the nearest equivalent rather than an interpolated exact value.