Convert carats to grams for diamond grading, jewelry appraisal, and precious metal trading. Accurate calculator with industry standards and real-world examples.
1 carat equals 0.2 gram
Formula: g = ct × 0.200000
The carat, equal to exactly 200 milligrams or 0.2 grams, is the standard unit for measuring gemstone and precious metal weight worldwide. Understanding this conversion is essential for jewelry professionals, gemologists, and collectors who work across different measurement systems. A single carat difference can represent thousands of dollars in diamond value.
Precision in carat-to-gram conversion directly impacts gemstone valuations, jewelry pricing, and international trade. A 1-carat diamond can cost $3,000-$15,000 depending on quality, making accurate conversion critical. Jewelers, appraisers, and gemologists must convert between carats and grams for inventory management, certification, and cross-border transactions. Errors in conversion can result in significant financial losses or legal disputes over gemstone authenticity and weight.
Jewelry manufacturers use carat-to-gram conversions when sourcing diamonds and gemstones, creating product specifications, and calculating material costs. Retailers convert weights for international customers, insurance documentation, and online product listings. The conversion ensures consistency across supply chains where some suppliers use carats while others use grams, particularly in European and Asian markets.
Gemological laboratories measure precious stones in carats for certification reports, but maintain gram measurements for internal records and quality control. The Gemological Institute of America (GIA) and similar organizations use carats as the standard for public reporting while using precise gram measurements for technical analysis. Conversion accuracy is critical for verifying gemstone authenticity and detecting weight discrepancies.
| carats | grams |
|---|---|
| 10 ct | 2 g |
| 50 ct | 10 g |
| 100 ct | 20 g |
| 500 ct | 100 g |
| 1000 ct | 200 g |
Formula: g = ct × conversion factor
The carat is a widely used unit for measuring weight. It is commonly used in various applications and industries worldwide.
The gram is a widely used unit for measuring weight. It is commonly used in various applications and industries worldwide.
This carat to gram converter uses high-precision conversion factors to ensure accurate results for professional and academic use.
Our calculator provides results with up to 10 decimal places for maximum accuracy.
One carat equals exactly 0.2 grams or 200 milligrams. This is the international standard established in 1913. To convert carats to grams, multiply the carat weight by 0.2. For example, a 2.5-carat diamond equals 0.5 grams. Conversely, to convert grams to carats, multiply by 5: 1 gram equals exactly 5 carats. This simple 1:5 relationship makes mental calculations straightforward for jewelry professionals.
Carats became the standard for gemstones because of historical tradition and practical advantages. Carob seeds were naturally uniform in weight and used for centuries as balance-scale references. The carat system persists because it's deeply embedded in gemstone grading, certification standards, and pricing psychology—consumers understand that a 1-carat diamond is a meaningful milestone. The metric system uses grams, but the gemstone industry maintained carats for consistency and because the 200mg standard aligns well with jewelry scales and traditional practices.
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