Energy is directly proportional to temperature: E = mc² = k•T
where E is the energy; k = 1.380 648 8(13)×10 ⁻²³ J/K is the Boltzmann constant, which relates the energy scale to the Kelvin temperature scale and T is the temperature.
Therefore, 1 J = 7.242 971 6(66) × 10²² K.
or 1 K = 1.380648780669 x 10-23 J