Kilograms Conversion

The kilogram, the base unit of mass in the International System of Units (SI), has a fascinating history tied to a physical artifact. Until 2019, it was defined by Le Grand K, a platinum-iridium cylinder stored in a vault in France. However, even slight surface contamination or material wear could alter its mass. To ensure a more stable and universally consistent measure, the kilogram is now defined by the Planck constant—a fundamental constant of nature—using a Kibble balance. This revolutionary change marked a significant milestone in metrology and brings mass measurement into line with other SI units that are already defined by fundamental constants, rather than physical objects.