Convert Carat (car, ct) to Kilogram (kg) 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.
Kilogram (kg)
The kilogram is the base unit of mass in the SI system and the only SI unit defined directly by a fundamental constant rather than a physical object. Originally, its definition was tied to a platinum–iridium artifact stored in France—the famous "International Prototype Kilogram." Over time, tiny mass changes in the prototype and its official copies created difficulties for high-precision science. In 2019, the kilogram was redefined using Planck's constant, linking mass to the laws of quantum physics through the Kibble balance. This innovation ensures universality, stability, and reproducibility across the world. The kilogram is central to commerce, science, engineering, and every quantitative field dealing with matter. Its decimal relationships with other metric units (grams, milligrams, tons) make it universally convenient. From groceries to spacecraft mass budgets, the kilogram anchors modern mass measurement.