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Ring Size Converter

Convert ring sizes between US, UK, EU, and Japanese sizing systems. Get diameter and circumference measurements.

Ring Size Converter

Convert ring sizes between US, UK, EU, and Japanese systems

How to Use This Converter

  1. 1

    Select your size system

    Choose US/Canada, UK/Australia, Europe, or Japan.

  2. 2

    Enter your ring size

    Input your known ring size in the selected system.

  3. 3

    View conversions

    See your ring size in all international systems plus diameter and circumference.

Frequently Asked Questions

How do I measure my ring size?

Wrap a string around your finger at the base, mark where it meets, and measure the length in mm (circumference). Or measure the inner diameter of a ring that fits well.

What if I'm between sizes?

If between sizes, choose the larger size. Fingers swell throughout the day and in warm weather, so a slightly larger ring is usually more comfortable.

Do ring sizes differ by country?

Yes, each country uses different sizing systems. US uses numbers (3-13), UK uses letters (A-Z), EU uses circumference in mm (40-70), and Japan uses numbers (1-27).