Ring Size Converter
Convert between US/CA, UK/AU, EU, JP/SG, HK/CH ring sizes.
Quick Ring Size Converter
Choose a standard, enter a size, and see the matching size plus measurements.
Comprehensive International Ring Size Chart
Already have a measurement? Use the chart below to understand how it fits into international standards.
| Diameter (mm) | Circumference (mm) | US & Canada | UK & Australia | EU | Japan & Singapore | Hong Kong | Switzerland |
|---|---|---|---|---|---|---|---|
| 14.1 | 44.1 | 3 | F | 44 | 4 | 7 | 4 |
| 14.3 | 44.8 | 3.25 | G | 45 | 5 | 7.5 | 5 |
| 14.4 | 45.4 | 3.5 | G 1/2 | 45.5 | 5.5 | 8 | 5.5 |
| 14.7 | 46.0 | 3.75 | H | 46 | 6 | 8.5-9 | 6 |
| 14.9 | 46.7 | 4 | H 1/2 | 47 | 7 | 9.5 | 7 |
| 15.0 | 47.3 | 4.25 | I | 47.5 | 7.5 | 10 | 7.5 |
| 15.3 | 48.0 | 4.5 | J | 48 | 8 | 10.5 | 8 |
| 15.4 | 48.4 | 4.75 | J 1/2 | 48.5 | 8.5 | 11 | 8.5 |
| 15.7 | 49.3 | 5 | K 1/2 | 49.5 | 9 | 11.5-12 | 9.5 |
| 15.9 | 50.0 | 5.25 | L | 50 | 9.5 | 12.5 | 10 |
| 16.1 | 50.6 | 5.5 | L 1/2 | 50.5 | 10.5 | 13 | 10.5 |
| 16.3 | 51.2 | 5.75 | M | 51 | 11 | 13.5 | 11 |
| 16.5 | 51.9 | 6 | M 1/2 | 52 | 12 | 14-14.5 | 12 |
| 16.7 | 52.5 | 6.25 | N | 52.5 | 12.5 | 15 | 12.5 |
| 16.9 | 53.2 | 6.5 | N 1/2 | 53 | 13 | 15.5 | 13 |
| 17.1 | 53.8 | 6.75 | O | 54 | 13.5 | 16 | 14 |
| 17.3 | 54.4 | 7 | O 1/2 | 54.5 | 14 | 16.5 | 14.5 |
| 17.5 | 55.1 | 7.25 | P | 55 | 14.5 | 17 | 15 |
| 17.7 | 55.7 | 7.5 | P 1/2 | 56 | 15 | 17.5 | 16 |
| 17.9 | 56.3 | 7.75 | Q | 56.5 | 16 | 18 | 16.5 |
| 18.1 | 57.0 | 8 | Q 1/2 | 57 | 16.5 | 18.5 | 17 |
| 18.3 | 57.6 | 8.25 | R | 57.5 | 17 | 19 | 17.5 |
| 18.5 | 58.3 | 8.5 | R 1/2 | 58.5 | 17.5 | 19.5-20 | 18.5 |
| 18.8 | 58.9 | 8.75 | S | 59 | 18 | 20.5 | 19 |
| 18.9 | 59.5 | 9 | S 1/2 | 59.5 | 18.5 | 21 | 19.5 |
| 19.1 | 60.2 | 9.25 | T | 60 | 19 | 21.5 | 20 |
| 19.4 | 60.8 | 9.5 | T 1/2 | 61 | 19.5 | 22 | 21 |
| 19.6 | 61.5 | 9.75 | U | 61.5 | 20 | 22.5-23 | 21.5 |
| 19.8 | 62.1 | 10 | U 1/2 | 62 | 21 | 23.5 | 22 |
| 20.0 | 62.7 | 10.25 | V | 63 | 22 | 24 | 23 |
| 20.2 | 63.4 | 10.5 | V 1/2 | 63.5 | 22.5 | 24.5 | 23.5 |
| 20.4 | 64.0 | 10.75 | W | 64 | 23 | 25 | 24 |
| 20.6 | 64.6 | 11 | W 1/2 | 64.5 | 24 | 25.5-26 | 24.5 |
| 20.8 | 65.3 | 11.25 | X | 65.5 | 25 | 26.5 | 25.5 |
| 21.0 | 65.9 | 11.5 | X 1/2 | 66 | 25.5 | 27 | 26 |
| 21.2 | 66.5 | 11.75 | Y | 66.5 | 26 | 27.5 | 26.5 |
| 21.4 | 67.2 | 12 | Y 1/2 | 67 | 27 | 28-28.5 | 27 |
| 21.6 | 67.8 | 12.25 | Z | 68 | 27.5 | 29 | 28 |
| 21.8 | 68.5 | 12.5 | Z 1/2 | 68.5 | 28 | 29.5-30 | 28.5 |
| 22.0 | 69.1 | 12.75 | Z+1 | 69 | 29 | 30.5 | 29 |
| 22.2 | 69.7 | 13 | Z+1 1/2 | 70 | 30 | 31-31.5 | 30 |
| 22.4 | 70.4 | 13.25 | Z+2 | 70.5 | 31 | 32 | 30.5 |
| 22.6 | 71.0 | 13.5 | Z+2 1/2 | 71 | 32 | 32.5-33 | 31 |
About these standards
Values are based on commonly referenced international charts. Manufacturers may vary; use as guidance.
- US/CA:
- Numeric scale with half sizes (e.g., 6, 6.5).
- UK/AU:
- Alphabetic scale with half-steps (e.g., M, M½).
- EU:
- Typically inner circumference in mm (e.g., 52, 53).
- JP/SG:
- Numeric scale (e.g., 12, 13).
- HK/CH:
- Local numeric scales that may differ from JP.
Your Ring Sizing Toolkit
Quick links to related sizing tools and resources.
Guides & Tips for Ring Size Conversion
How to read conversion results, avoid size mismatches, and pick the right standard for purchases.
1. Master international ring size conversion methods with step-by-step guides for accurate cross-border jewelry shopping.
- Measure the inner diameter of your existing ring with a ruler, then use our converter to translate measurements between US, UK, and European standards.
- Calculate finger circumference with string or tape measure, then divide by 3.14 to get diameter for accurate international size conversion.
- Use printable ring size charts at exact 100% scale to compare your ring against international size standards for reliable reference matching.
- Understand that US uses numeric (3-13), UK uses alphabetical (A-Z), while Europe uses millimeter measurements based on inner circumference.
- Our online international converter instantly handles all conversions between major sizing systems, eliminating calculation errors for global purchases.
2. Understand the relationship between different measurement units for accurate ring sizing with mm, inches, and circumference conversions.
- Ring sizes are determined by diameter (distance across the center) or circumference (distance around the finger), with 1 inch equaling 25.4mm.
- Convert millimeters to inches by dividing by 25.4, or inches to millimeters by multiplying by 25.4 for precise size calculations.
- US size 6 equals approximately 16.5mm diameter and 52mm circumference, providing a reference point for size estimation.
- European sizing uses inner circumference in millimeters (typically 50-60mm), while US uses numeric scale based on diameter measurements.
- Our ring size converter instantly calculates equivalent sizes across all measurement system, unit and ring size standards, ensuring accurate conversions for global jewelry shopping.
3. Compare average ring sizes across different countries and understand international sizing systems for global jewelry shopping.
- US sizes 6-7 are most common for women (equivalent to UK O-P and Europe 54-56), while US 9-11 are typical for men internationally.
- Asian countries generally have smaller average sizes - US 3-5 is considered normal in many Asian markets compared to Western averages.
- European sizing uses millimeter measurements (typically 50-60mm), while UK uses alphabetical letters, requiring conversion for accurate shopping.
- US and Canada share identical numeric sizing systems (3-13), making cross-border purchasing between North America seamless.
- Use our international converter tool to instantly translate any country's ring size to US standards for confident global online jewelry shopping.
4. Explore standard ring size ranges across different countries and regions to understand normal sizing conventions worldwide.
- US standard ring sizes typically range from 3-13 for women and 8-14 for men, with half sizes available for precise fitting in North America.
- UK and Australian markets use alphabetical sizing (G-R for women, S-Z for men), offering different size ranges than the numeric US system.
- European countries use millimeter measurements based on inner diameter, typically ranging from 46-64mm for women's standard sizes.
- Japanese ring sizes follow a numeric system (1-27) with different increments than Western sizing, requiring careful conversion for international purchases.
- Use our comprehensive ring size chart, converter and visualizer to compare your size across all international standards, ensuring you select the correct size regardless of where you shop globally.
5. Avoid these common ring sizing mistakes to prevent costly resizing issues.
- Don't measure your finger at the wrong time - avoid measuring when hands are cold, in the morning, or after exercise when fingers are swollen.
- Never ignore finger shape and band width - wider bands require larger sizes, and finger shape affects how rings fit differently.
- Don't rely on string or paper measurements alone - these methods often result in inaccurate sizing and costly mistakes.
- Avoid guessing based on shoe size or other body measurements - ring sizes have completely different sizing systems.
- Always double-check your measurements before purchasing - use our online calculator to verify your precise size.
6. Learn how to use our four essential ring size tools strategically based on your specific needs and shopping scenarios.
- Use the ring size calculator when you have an existing ring - simply enter your measurements to determine its exact size for replacement or matching purchases.
- Turn to the ring size converter for international shopping - instantly convert between US, UK, European, and Japanese standards when buying from overseas retailers.
- Reference the ring size chart for quick comparisons - view all sizes at once to find your size range and understand half-size differences before making decisions.
- Use the ring size visualizer when you need to see actual size - view real-scale rings on screen to understand how different sizes will look and feel on your hand.
- Combine multiple tools for complete accuracy: use the calculator for precise measurement, converter for international standards, chart for comparison, and visualizer for visual confirmation.
About Sizepedia
A data-driven size knowledge base providing standards, datasets and practical tools.
Sizepedia.com is a size-focused encyclopedia and toolkit: we collect and curate public standards, manufacturer size charts, and industry references to build consistent conversion tables and reference data that clarify how different systems correspond. We currently prioritize and publish features for ring sizing, including online measurement tools, international conversion tables, and brand mappings. Over time we will expand to footwear, apparel, and additional sizing categories to deliver more data and practical tools. Our resources are provided as a best-effort guide to help you choose sizes with confidence; when an exact fit matters, combine our guidance with local measurement or manufacturer recommendations for final confirmation.
Want more sizes or brands covered? Tell us — help Sizepedia.com grow.