Gemstone Calculator: Estimate Weight & Properties of Your Gems

Calculate Your Gemstone's Estimated Weight (Carats)

Common SG values: Diamond (~3.52), Ruby (~4.00), Sapphire (~4.00), Emerald (~2.72).

Unlock the mysteries of your precious stones with our intuitive Gemstone Calculator. This free online tool helps you estimate gemstone weight in carats based on dimensions, understand specific gravity, and get a better sense of your gem's properties. Perfect for gem enthusiasts, jewelers, and anyone curious about their sparkling treasures.

Formula:

Estimated Weight (Carats) ≈ Length (mm) × Width (mm) × Depth (mm) × Specific Gravity (SG) × 0.002

Variables:

  • Length: The longest dimension of the gemstone (in millimeters).
  • Width: The shortest dimension of the gemstone (in millimeters).
  • Depth: The height of the gemstone from table to culet (in millimeters).
  • Specific Gravity (SG): A dimensionless ratio of the density of the gemstone to the density of water (e.g., Diamond ≈ 3.52, Ruby ≈ 4.00, Sapphire ≈ 4.00, Emerald ≈ 2.72).
  • 0.002: An approximate conversion factor to estimate carats from dimensions and specific gravity for various cuts. (Note: More precise factors exist for specific shapes like round brilliant, oval, emerald cut, etc. This calculator provides an estimation.)

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