The basic unit of thermodynamic temperature in the international system of units (→ SI units). The kelvin is also the fundamental unit of the → Kelvin scale. One kelvin represents the same temperature difference as one degree → Celsius. It was previously called the degree Kelvin (°K).
Named after the Scottish physicist William Thomson, also known as Lord Kelvin (1824-1907), one of the most influential scientists of the 19th century.