Ring Size Chart in Centimeters: Quick CM Conversion Guide

Convert ring sizes to centimeters with our simple chart. Find US, UK, and EU ring sizes in cm measurements for accurate international sizing.

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Ring Sizing

Ring Size Chart in Centimeters: Quick CM Conversion Guide

When shopping for rings internationally or working with precise measurements, understanding ring sizes in centimeters makes sizing universal and accurate.

Why Use Centimeters for Ring Sizing?

  • Universal measurement: Understood worldwide
  • High precision: More accurate than approximate conversions
  • International shopping: Essential for global purchases
  • Professional standard: Used by jewelers internationally

Ring Size Chart in Centimeters

US Sizes to Centimeters

| US Size | Circumference (cm) | Diameter (mm) | |---------|-------------------|---------------| | 4 | 4.68 cm | 14.9 mm | | 5 | 4.93 cm | 15.7 mm | | 6 | 5.18 cm | 16.5 mm | | 7 | 5.44 cm | 17.3 mm | | 8 | 5.70 cm | 18.1 mm | | 9 | 5.95 cm | 18.9 mm | | 10 | 6.21 cm | 19.8 mm | | 11 | 6.46 cm | 20.6 mm |

UK Sizes to Centimeters

| UK Size | Circumference (cm) | US Equivalent | |---------|-------------------|---------------| | H | 4.68 cm | US 4 | | J | 4.93 cm | US 5 | | L | 5.18 cm | US 6 | | N | 5.44 cm | US 7 | | P | 5.70 cm | US 8 | | R | 5.95 cm | US 9 | | T | 6.21 cm | US 10 |

European Sizes to Centimeters

| EU Size | Circumference (cm) | US Equivalent | |---------|-------------------|---------------| | 47 | 4.68 cm | US 4 | | 49 | 4.93 cm | US 5 | | 52 | 5.18 cm | US 6 | | 54 | 5.44 cm | US 7 | | 57 | 5.70 cm | US 8 | | 60 | 5.95 cm | US 9 | | 62 | 6.21 cm | US 10 |

How to Measure Ring Size in Centimeters

Method 1: String Measurement

  1. Wrap string around your finger
  2. Mark where it overlaps
  3. Measure the length in centimeters
  4. Find your size in the chart above

Method 2: Existing Ring

  1. Measure the inner circumference of a well-fitting ring
  2. Use a flexible measuring tape for accuracy
  3. Convert the centimeter measurement using our chart

Converting Between Diameter and Circumference

Formula: Circumference = Diameter × 3.14159

Common conversions:

  • 1.49 cm diameter = 4.68 cm circumference (US 4)
  • 1.65 cm diameter = 5.18 cm circumference (US 6)
  • 1.73 cm diameter = 5.44 cm circumference (US 7)
  • 1.89 cm diameter = 5.95 cm circumference (US 9)

Tips for Accurate CM Measurements

Best practices:

  • Measure at the end of the day when fingers are largest
  • Use a flexible measuring tape for curved measurements
  • Take multiple measurements for consistency
  • Consider ring width - wider bands need larger sizes

Avoid these mistakes:

  • Measuring when fingers are cold (they shrink)
  • Pulling the measuring tape too tight
  • Forgetting to account for knuckle size
  • Mixing up diameter and circumference measurements

Ring Width Adjustments in CM

For rings wider than 4mm, add to your measurement:

  • 5-6mm bands: Add 0.1 cm
  • 7-8mm bands: Add 0.2 cm
  • 9mm+ bands: Add 0.3 cm

Average Ring Sizes in Centimeters

Women's average: 5.18 cm (US size 6) Men's average: 6.21 cm (US size 10) Typical range: 4.5 cm to 7.0 cm

When to Use CM Measurements

Centimeter measurements are especially useful for:

  • International online shopping
  • Custom jewelry orders
  • Professional jewelry making
  • Precise sizing requirements
  • Gift purchases when exact sizing is crucial

Quick Reference: Popular Sizes

Most common women's sizes:

  • 4.93 cm = US 5 = UK J
  • 5.18 cm = US 6 = UK L
  • 5.44 cm = US 7 = UK N

Most common men's sizes:

  • 5.95 cm = US 9 = UK R
  • 6.21 cm = US 10 = UK T
  • 6.46 cm = US 11 = UK V

Using centimeter measurements ensures accuracy across all international sizing systems. When in doubt, professional measurement by a jeweler remains the most reliable option for expensive purchases.

Need more sizing help? Use our ring size converter or try our ring size finder tool.