According to the law of equipartition of energy the energy associated with each degree of freedom is 

Energy associated with each degree of freedom is $\frac{1}{2}{\mathrm{k}}_{\mathrm{B}}\mathrm{T}$

Law of equipartition of energy states that for a dynamical system in thermal equilibrium the total energy of the system is shared equally by all the degrees of freedom. The energy associated with each degree of freedom per molecule is$\frac{1}{2}{\mathrm{K}}_{\mathrm{B}}\mathrm{T}$, where K_B is the Boltzmann’s constant.

For example, for a monoatomic molecule each molecule has 3 degrees of freedom.  According to kinetic theory of gases, the mean kinetic energy of a molecule is $\frac{3}{2}{\mathrm{K}}_{\mathrm{B}}\mathrm{T}$