Boltzmann constant

The Boltzmann constant ($k$ or $k_B$) is the physical constant relating temperature to energy.

It is named after the Austrian physicist Ludwig Eduard Boltzmann. Its experimentally determined value (in SI units, 2002 CODATA value) is:

$k_B=1.3806505(24)\times 10^{-23}$ joule/kelvin

$=8.617343(15)\times 10^{-5}$ electron-volt/kelvin.