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Carat Weight Formula:
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The carat weight calculation estimates a gemstone's weight based on its physical dimensions and shape. This is particularly useful when you can measure the stone but don't have access to precise weighing scales.
The calculator uses the formula:
Where:
Explanation: Different gemstone shapes have different volume distributions, hence the shape-specific factors account for these variations in the calculation.
Details: Accurate carat weight estimation helps in gemstone valuation, setting design, and when comparing stones of similar size. It's especially useful for mounted stones that cannot be weighed directly.
Tips: Measure dimensions in millimeters using precise calipers. Select the appropriate shape factor from the dropdown. All values must be positive numbers.
Q1: How accurate is this calculation?
A: The calculation is typically within 5-10% of actual weight, depending on measurement precision and how well the stone matches the ideal shape proportions.
Q2: Why different factors for different shapes?
A: Different shapes distribute their mass differently. For example, round brilliants have more weight concentrated in the pavilion than marquise cuts.
Q3: Can I use this for all gemstones?
A: These factors are optimized for diamonds. Other gemstones with different specific gravities may need adjusted factors.
Q4: What's the most accurate way to measure dimensions?
A: Use digital calipers on an unmounted stone, measuring to the nearest 0.01mm at the stone's widest points.
Q5: How does cut affect the calculation?
A: The shape factors account for standard cut proportions. Exceptionally deep or shallow stones may have slightly different actual weights.