In statistical thermodynamics, thermodynamic beta, also known as coldness, is the reciprocal of the thermodynamic temperature of a system: β = 1 k B T {\displaystyle \beta ={\frac {1}{k_{\rm {B}}T}}} (where T is the temperature and kB is Boltzmann constant).
Thermodynamic beta has units reciprocal to that of energy (in SI units, reciprocal joules, [ β ] = J − 1 {\displaystyle [\beta ]={\textrm {J}}^{-1}} ). In non-thermal units, it can also be measured in byte per joule, or more conveniently, gigabyte per nanojoule; 1 K−1 is equivalent to about 13,062 gigabytes per nanojoule; at room temperature: T = 300K, β ≈ 44 GB/nJ ≈ 39 eV−1 ≈ 2.4×1020 J−1. The conversion factor is 1 GB/nJ = 8 ln 2 × 10 18 {\displaystyle 8\ln 2\times 10^{18}} J−1.