Diamond Weight Calculator
Calculate diamond weight in carats from dimensions
Diamond Shape & Dimensions
Adjustments (Optional)
Very Thin to Thin
Adjust for non-standard proportions
What is a Carat?
• 200 milligrams
• 0.2 grams
• 0.007055 ounces
The carat unit was standardized over a century ago and is the universal measure for gemstone weight.
Girdle Thickness Guide
Shape Corrections
Wide Wings/Shoulders
Pear: +1% to +5%
Marquise, Oval, Heart: +1% to +10%
Large Culet
All shapes: +1% to +2%
Wide Corners
Emerald, Radiant: -1% to -5%
Diamond Tips
Round diamonds are the most popular, representing 75% of all sales
Fancy shapes are often less expensive than equivalent round diamonds
Diamond prices don't increase proportionally with weight
This calculator provides estimates - actual weight may vary
Understanding Diamond Weight Calculation
Diamond Weight Formulas
Diamond weight calculation varies by shape, using specific density factors derived from geometric properties and industry standards. Each shape has its own formula based on how light travels through the diamond and its cutting requirements.
Factors Affecting Accuracy
- •Girdle Thickness: Affects the diamond's overall mass
- •Cut Quality: Proportions affect weight distribution
- •Shape Variations: Non-standard proportions require corrections
- •Measurement Precision: Small errors compound significantly
Diamond Value Factors
The 4 Cs
• Cut: Quality of proportions and polish
• Carat: Weight of the diamond
• Clarity: Presence of inclusions
• Color: Absence of color (for white diamonds)
Additional Factors
• Fluorescence: Reaction to UV light
• Certification: GIA, AGS, etc.
• Shape: Round vs. fancy shapes