Ring Size Converter
Convert ring sizes across US, UK, EU, JP, cm and inch — instantly in your browser.
About This Tool
Ring Size Converter translates one measurement into every major sizing standard using ISO-based inner diameter and circumference references. All calculations run locally — nothing leaves your device.
How To Use
- Enter your known ring size and select its system.
- Equivalent sizes update automatically in real time.
- Convert refreshes manually; Copy copies the full result; Clear resets everything.
Input
All Sizes
Enter a ring size to see all corresponding measurements.
Inner circumference
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Sizing Notes
- US — Numeric scale; half sizes supported (e.g. 6.5).
- UK — Letter scale A–Z; half sizes as K½ or K 1/2.
- EU — Inner circumference in millimeters (e.g. 54).
- JP — Inner diameter in millimeters (e.g. 15).
- cm — Inner circumference in centimeters (e.g. 5.44).
- inch — Inner diameter in inches (e.g. 0.677).