Planck Energy

In physics, the unit of energy in the system of natural units known as Planck units is called the Planck energy, denoted by $E_P$. $E_P$ is a derived, as opposed to basic, Planck unit. An equivalent definition is:$E_P = \hbar / T_P$ where $T_P$ is the Planck time. Also: $E_P = m_P c^2$ where $m_P$ is the Planck mass.