kilogramKelvin

Kilogram kelvin is a nonstandard, dimensionful unit formed by the product of the SI base units for mass (kilogram) and thermodynamic temperature (kelvin). It is not part of the International System of Units (SI) and has no official designation as a measured quantity. As a result, kg·K has no corresponding SI quantity, and it is generally treated as a composite unit rather than a recognized unit for a specific physical property.

In practice, kilogram kelvin appears mainly in software, data analysis, or dimensional analysis exercises where a single unit is used to track the product of quantities with different dimensions. It is not typically used in formal scientific reporting, because combining mass and temperature into a single unit can obscure the underlying physical meaning and risk misinterpretation. When a specific quantity is required, it is clearer to use standard units that map to a defined physical quantity (for example, energy in joules or heat capacity in J/(kg·K)) or to keep mass and temperature separate.

Notation for the unit is commonly kg·K or sometimes written as kgK, but such usage is informal and not standardized. The lack of standard meaning means that any use of kg·K should be accompanied by a clear definition of what it represents in that context. See also: SI base units, dimensional analysis, derived units.