## Background

The electron was described in the electron mass page as a stable particle and a key component of the atom. In physics equations, electron mass is commonly used, but the electron’s rest energy is equally important because its mass is derived from energy. The only difference between the two is wave speed squared (c^{2}).

Particle energies including the electron, were calculated as standing, longitudinal waves with wave amplitudes that decrease at distance from the particle core until reaching incoming wave amplitude, once again becoming traveling waves. Wave amplitude, wavelength and the particle radius where standing waves transition to traveling waves are all proportional to the number of wave centers (K).

See also: Electron Mass

## Derivation – Electron Energy

The electron’s rest energy can be derived classically from the Planck mass, Planck length, Planck time, electron radius and fine structure constant. In wave format, is derived from the Longitudinal Energy Equation. It is simply longitudinal, standing wave energy, when a particle consists of ten wave centers (K=10). Electron energy is calculated as in-waves and out-waves that create standing waves to the electron’s classical radius where the waves become traveling in form again.

## Classical Constant Form |
## Wave Constant Form |

Using classical constants | Using energy wave constants |

**Calculated Value: **8.1871E-14

**Difference from CODATA:** 0.000%

**Calculated Units**: Joules (kg m^{2}/s^{2})

**Alternative Derivation**

An alternative derivation in classical form is shown with the magnetic constant, elementary charge and speed of light. This version shows the consistency of energy and mass equations in classical format, as explained on the page for Coulomb’s constant.

Its value was calculated and shown to match the known value in the Summary of Calculations table. *The derivation of this constant is available in the Fundamental Physical Constants paper.*