Convert Carat (car, ct) to Grain (gr) instantly.
About these units
Carat (car, ct)
The carat, equal to 200 milligrams, is the standard unit for measuring gemstones and pearls. Its origins trace to the seeds of the carob tree, which were historically thought to have remarkably uniform mass, making them convenient reference weights for early traders. In the modern gem trade, carats measure both weight and (informally) influence perceived value—though size and quality factors such as clarity and color also play major roles. High-precision digital scales capable of reading to 0.001 carat are common in gemology. The carat's persistence shows how specialized units evolve to meet the needs of niche industries. Though small, its economic impact is enormous due to the value of gemstones.
Grain (gr)
The grain, defined as exactly 64.79891 milligrams, is one of the oldest units of mass still in limited use today. Derived from the weight of average cereal grains such as barley or wheat, it became a universal tiny unit used across Europe for coins, medicine, and gunpowder. The grain persists in firearms and ammunition manufacturing because bullet weights are still listed in grains (e.g., a "150-grain bullet"). Reloaders and ballistic engineers rely on the grain as a fine unit suitable for measuring powder charges and projectile masses. It is also used in traditional gold and silver transactions, linking it to the troy system. The grain's longevity highlights how ancient agrarian measures can remain embedded in modern technological practices.