Boltzmann constant

For the constant pertaining to energy of black body radiation see Stefan–Boltzmann constant

Values of k	Units
1.3806488(13)×10−23	J K−1
8.6173324(78)×10−5	eV K−1
1.3806488(13)×10−16	erg K−1

The Boltzmann constant (k or k_B) is a physical constant. It relates the average kinetic energy of a particle in a gas with the temperature of the gas. It is the gas constant R divided by the Avogadro constant N_A:

$k={\frac {R}{N_{\rm {A}}}}\,$

The Boltzmann constant has SI units of J⋅K⁻¹, the same as entropy. It is named after the Austrian physicist Ludwig Boltzmann.