Kilograma

Kilograma, commonly called kilogram in English, is the SI base unit of mass. Its symbol is kg, and one kilogram equals 1000 grams. The kilogram is used as the standard for measuring mass in science, industry, and daily life.

Definition and realization: Since May 20, 2019, the kilogram is defined by fixing the numerical value of the Planck constant h to exactly 6.62607015×10^-34 J·s. Mass is realized by linking it to h through precision instruments such as the Kibble (watt) balance and the Avogadro project’s silicon-sphere method, providing a definition tied to fundamental constants rather than a physical artifact. Until 2019, the kilogram was defined by the mass of the International Prototype Kilogram, a platinum–iridium sculpture kept at the BIPM in Sèvres, France, with copies used as reference standards.

Usage and context: The kilogram is used with SI prefixes to cover a wide range of masses, from milligrams to megagrams. It is the standard unit for most everyday mass measurements, including body weight in many countries. In practical terms, 1 kilogram is approximately 2.20462 pounds. In various languages, the term Kilograma is used as the localized form of the unit, while the official SI designation remains kilogram with the symbol kg.

See also: The kilogram remains central to precision metrology and international trade, serving as the foundational reference for mass measurements worldwide.