Convert carats to grains for gemstone valuation, jewelry manufacturing, and precious metal weighing. Accurate calculator with industry-standard conversion factors.
1 carat equals 3.08648 grain
Formula: gr = ct × 3.08647
Understanding carat to grain conversion is essential for jewelry professionals, gemologists, and precious metal dealers. One carat equals precisely 3.086471 grains, a distinction critical when dealing with high-value gemstones and diamonds where even small measurement errors translate to significant financial discrepancies. This conversion bridges two measurement systems used across different sectors of the precious goods industry.
Precision in carat-to-grain conversion directly impacts gemstone pricing, insurance valuations, and international trade. A single carat difference on a diamond can represent thousands of dollars in value. Jewelry manufacturers must maintain exact weight specifications for custom pieces, while gemologists require accurate conversions when certifying stones for auction houses and collectors. Errors in conversion can result in legal disputes, insurance claim denials, and damaged professional reputation.
Jewelry manufacturers use carat-to-grain conversions when sourcing gemstones from international suppliers who may use different measurement standards. Precision is critical when creating custom engagement rings, luxury watches, and high-end jewelry pieces where exact weight specifications are contractually binding. Manufacturers must verify supplier weights and ensure finished pieces meet customer specifications and regulatory requirements.
Gemologists and certified appraisers use grain conversions when verifying gemstone weights across different measurement systems and historical records. Auction houses require precise weight documentation in multiple units for international buyers. Museums and collectors often encounter historical gemstone records that use grains, necessitating accurate conversion to modern carat standards for appraisal and insurance purposes.
| carats | grains |
|---|---|
| 1 ct | 3.08648 gr |
| 10 ct | 30.8648 gr |
| 25 ct | 77.162 gr |
| 50 ct | 154.324 gr |
| 100 ct | 308.648 gr |
Formula: gr = ct × conversion factor
The carat is a widely used unit for measuring weight. It is commonly used in various applications and industries worldwide.
The grain is a widely used unit for measuring weight. It is commonly used in various applications and industries worldwide.
This carat to grain 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.
Exactly 3.086471 grains equal one carat. This precise conversion factor is based on the metric carat definition of 200 milligrams and the avoirdupois grain definition of 64.79891 milligrams. For practical jewelry work, 3.0865 grains (rounded to 4 decimal places) provides sufficient accuracy. For example, a 5-carat gemstone equals 15.43236 grains. This precision matters significantly in high-value transactions where even small weight variations impact pricing substantially.
Historical gemstone documentation, particularly from British, European, and early American jewelry sources, frequently used grains because the avoirdupois system dominated weight measurements before metric standardization. The metric carat was officially adopted internationally in 1907, but older certificates, estate jewelry documentation, and antique appraisals often retained grain measurements. Modern appraisers convert these historical grain measurements to carats for current insurance valuations and certification. Understanding both systems is essential for authenticating and appraising inherited jewelry and estate collections.
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