Convert Carat (car, ct) to Pennyweight (pwt) 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.
Pennyweight (pwt)
The pennyweight, equal to 1/20 of a troy ounce or 1.55517384 grams, is a unit used primarily in the precious metals and jewelry industries. Its origins lie in medieval English coinage, when the weight of silver pennies provided a practical standard for small masses. Jewelers continue to use the pennyweight because many traditional pricing structures and metalworking conventions are built around troy-based subdivisions. For gold, silver, and dental alloys, the pennyweight remains easier to work with than grams due to long-established norms. Even though the metric system is now dominant scientifically, the pennyweight persists because industries tied to history—especially those involving money and precious goods—tend to maintain deeply rooted practices.