Gemstone Weight Calculator

Calculate gemstone carat weight by shape, dimensions, and type using our Gemstone Carat Weight Calculator. Ideal for jewelers and gem enthusiasts.
Round Round
Emerald Emerald
Oval Oval
Marquise Marquise
Trillion Trillion
Radiant Radiant
Pear Pear
Heart Heart
Cushion Cushion
Asscher Asscher
Princess Princess
Value: 0%
Value: 0%
Estimated Weight: 0.00 carats

Weight = Length × Width × Depth. All shape factors (calculated for each size within a given shape) were then averaged to arrive at a single factor.

Traditionally, a gemstone’s weight is expressed in carats (1 carat = 0.20 grams or 200 milligrams). For gemstones weighing less than 1 carat, their weight is expressed in units that are 100 times smaller, known as points (e.g., 50 points = 0.5 carats).

When selecting a gemstone—whether for astrological significance, personal adornment, or investment—it’s essential to consider several key factors that influence its beauty, effectiveness, and value:

  • Carat Weight: Larger gemstones are generally rarer and can be more valuable. However, size alone doesn’t determine a gem’s worth.
  • Quality Over Size: The gemstone’s quality, encompassing color, clarity, and overall condition, is often more critical than its carat weight. A smaller, high-quality gem can be more desirable than a larger, flawed one.
  • Cut and Shape: The cut affects a gemstone’s brilliance and how light reflects within it, impacting its visual appeal and value. Well-proportioned cuts enhance sparkle and can make gems appear larger and more vibrant.

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Unmounted Morganite gemstones