Boltzmann constant

The Boltzmann constant (k_B or k), named after Ludwig Boltzmann, is a physical constant relating energy at the individual particle level with temperature. It is the gas constant R divided by the Avogadro constant N_A:

The Boltzmann constant has the dimension energy divided by temperature, the same as entropy. The accepted value in SI units is 6977138064851999999♠1.38064852(79)×10 J/K.