Kilogram (kg)
The kilogram (kg) is the SI base unit of mass.
- Origin
- Once defined by a platinum-iridium prototype, it has been defined since 2019 by fixing the Planck constant.
- Where it is used
- Used for material densities, structural loads, equipment weights and specifications worldwide.
- Relation to SI
- The kilogram is the SI base unit; all other mass units here derive from it.