Convert Carat (car, ct) to Petagram (Pg) 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.
Petagram (Pg)
A petagram, equal to 10¹² kilograms, is used almost exclusively in global environmental science and earth system modeling. Planetary-scale carbon budgets—for example, the total carbon stored in Earth's soils or forests—are expressed in petagrams. The Amazon rainforest alone holds on the order of 100 Pg of carbon. Using petagrams helps researchers track changes in Earth's climate balance and evaluate feedback loops in the carbon cycle.