The kilogram is the base unit of mass in the International System of Units. It is central to science, commerce and engineering.
The kilogram was first related to water, then to a physical prototype, and since 2019 has been defined by fixing the numerical value of the Planck constant.
Measurement system: International System of Units (SI). SI equivalent: Base SI unit of mass.
Kilogram facts
- Unit name
- Kilogram
- Symbol
- kg
- Category
- Mass
- Measurement system
- International System of Units (SI)
- SI equivalent
- Base SI unit of mass
- Common uses
- Commerce, transport, laboratories and process calculations
Definition of the kilogram
The kilogram is the base unit of mass in the International System of Units. It is central to science, commerce and engineering.
Measurement system and SI relationship
International System of Units (SI)
SI equivalent: Base SI unit of mass
History of the kilogram
The kilogram was first related to water, then to a physical prototype, and since 2019 has been defined by fixing the numerical value of the Planck constant.
Where is the kilogram used?
Commerce, transport, laboratories and process calculations