Ring Size Converter

Convert between US, UK, European, Japanese ring sizes and diameter measurements with precision

Printable Accurate Mobile Friendly

Ring Size Converter

Input Size

Converted Sizes

Enter a size above to see conversions

Printable Ring Sizer

Get a physical ring size chart for accurate measurements

Ring Size Chart Preview (US Sizes)

How to Use

Measuring Your Ring Size

  • Use a string or paper strip
  • Wrap around finger at base
  • Mark where it overlaps
  • Measure length in millimeters
  • Use our converter to find your size

Size Systems

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US: Numeric (3-15, half sizes)
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UK: Letters (A-Z, incl. half sizes like F+, and Z+1 to Z+4)
๐Ÿ‡ช๐Ÿ‡บ
EU: Numeric (44-75, half sizes)
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JP: Numeric (1-30)
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mm: Diameter measurement

Complete Guide to Ring Sizing

Why Accurate Ring Sizing Matters

Finding the perfect ring size is crucial for comfort and preventing loss. A ring that's too tight can cause discomfort and restrict blood flow, while a ring that's too loose may slip off and get lost. Our free ring size converter helps you find the perfect fit across all international sizing systems including US, UK, European, and Japanese standards.

How to Measure Your Ring Size at Home

Measuring your ring size at home is simple with our printable ring sizer. Follow these steps for the most accurate measurement:

  1. Print our ring sizer chart at 100% scale (no scaling)
  2. Verify the calibration mark measures exactly as indicated
  3. Place an existing ring over the circles on the chart
  4. Match the inner diameter of your ring to a circle
  5. Note the size and use our converter for other systems

For best results, measure at the end of the day when your fingers are at their largest, and measure multiple times to ensure consistency.

Understanding International Ring Size Systems

Different countries use different ring sizing systems, which can cause confusion when shopping internationally. Here's what you need to know:

US Sizes: The United States uses a numerical system ranging from 3 to 15, with half sizes (e.g., 6.5, 7.5) available. This is one of the most straightforward systems and is widely used in online jewelry stores.
UK Sizes: The United Kingdom uses an alphabetical system from A to Z, with half sizes denoted by a plus sign (e.g., F+, M+). After Z, the system continues with Z+1, Z+2, Z+3, and Z+4 for larger sizes.
European (EU) Sizes: European sizes use a numerical system based on the inner circumference of the ring in millimeters, typically ranging from 44 to 75. Half sizes are available and commonly used across continental Europe.
Japanese (JP) Sizes: Japan uses a numerical system from 1 to 30, which corresponds to specific diameter measurements. This system is primarily used in Japan and some Asian countries.

Professional Tips for Ring Sizing

  • Measure your ring size at different times of day, as fingers can swell during the day
  • Temperature affects finger size - measure in a comfortable, moderate environment
  • If between sizes, choose the larger size for comfort
  • Wide bands (over 8mm) typically require a size up for comfort
  • Different fingers on the same hand may require different sizes
  • When in doubt, visit a local jeweler for professional sizing

Common Ring Sizing Mistakes to Avoid

Many people make these common errors when determining their ring size:

  • Measuring when fingers are cold or swollen
  • Using a ring from a different finger for reference
  • Not accounting for knuckle size when the ring needs to pass over it
  • Printing the sizing chart with incorrect scale settings
  • Guessing size based on shoe size or other body measurements (there's no correlation!)

Why Use Our Ring Size Converter?

Our ring size converter is completely free, requires no registration, and provides instant, accurate conversions between all major international sizing systems. Whether you're shopping from an international retailer, buying a gift, or need to convert an existing ring size, our tool makes the process simple and reliable. The printable ring sizer chart is calibrated to industry standards and has helped thousands of people find their perfect ring size.