The constant is named after Ludwig Boltzmann, a 19th-century Austrian physicist, who substantially contributed to the foundation and development It defines the relationship between absolute temperature and the kinetic energy present in a molecule of an ideal gas. It is the ratio of gas constant(R) to Avogadro constant (NA). In thermodynamics, Boltzmann constant is the physical constant relating average kinetic energy of the gas particles and temperature of the gas represented by k or kB. Boltzmann constant, (symbol k), a fundamental constant of physics occurring in nearly every statistical formulation of both classical and quantum physics. Boltzmann's constant value is 1.3806488(13)×10 −23 J/K in SI units. The value of Boltzmann constant is measured using J/K or m 2 Kgs -2 K -1 . Boltzmann constant k B and Kelvin temperature T (300°K(=27°C) = k B T = 1/40 eV); thus T o = 37°C is slightly higher thermal reservoir energy. i.e., K = R/ NA. The Boltzmann constant (kB or k), named after its 19th century Austrian discoverer, Ludwig Boltzmann, is a physical constant that relates the average relative kinetic energy of particles in a gas with the temperature of the gas. Boltzmann's constant, also called the Boltzmann constant and symbolized k or k B, defines the relation between absolute temperature and the kinetic energy contained in each molecule of an ideal gas.This constant derives its name from the Austrian physicist Ludwig Boltzmann (1844-1906), and is equal to the ratio of the gas constant to the Avogadro constant. Boltzmann Constant is a physical constant named after Ludwig Boltzmann. It occurs in the definitions of the kelvin and the gas constant, and in