Ring Size Calculator – International Size Converter
Convert between US, UK, EU, and JP ring size standards
Table of Contents
How to Use
- Choose measurement type (circumference or diameter)
- Enter your measurement in millimeters
- Click calculate to see your size in all standards
- View equivalent sizes for US, UK, EU, and JP
How to Measure Ring Size
To measure your ring size accurately, you can use either a ring sizer tool or measure an existing ring that fits well. For best results, measure at the end of the day when fingers are slightly larger.
- Use a flexible measuring tape or string to measure finger circumference
- Measure the inside diameter of a ring that fits well
- Ensure the ring can slide over your knuckle comfortably
- Measure multiple times for accuracy
International Ring Size Standards
Different countries use different ring sizing systems. This calculator converts between the most common standards:
- US/Canada: Numerical system (3-15)
- UK/Australia: Letter system (F-Z+)
- Europe: Millimeter-based system (44-76)
- Japan: Numerical system (4-28)
Ring Sizing Tips
- Fingers can swell in hot weather or after exercise
- Measure at different times to find average size
- Consider width - wider bands fit tighter
- If between sizes, choose the larger size
- Visit a jeweler for professional sizing
Frequently Asked Questions
- How accurate is this ring size calculator?
- This calculator provides accurate conversions based on standard international sizing charts. However, for important purchases, we recommend getting professionally sized at a jewelry store.
- Can I measure my ring size at home?
- Yes, you can measure using a flexible tape measure or by measuring an existing ring. Measure the inside diameter or circumference in millimeters and enter it into this calculator.
- Why do ring sizes vary between countries?
- Different countries developed their own sizing systems historically. The US uses numbers, UK uses letters, Europe uses millimeters, and Japan has its own numerical system.
- Should I size up for wider rings?
- Yes, wider bands (over 6mm) typically require a half to full size larger than your regular ring size because they cover more surface area of your finger.
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