text: The Butler–Volmer equation is:
  or in a more compact form:
  where:
  * : electrode current density, A/m (defined as j = I/S)
  *: exchange current density, A/m
  * : electrode potential, V
  * : equilibrium potential, V
  * : absolute temperature, K
  * : number of electrons involved in the electrode reaction
  * : Faraday constant
  * : universal gas constant
  *: so-called cathodic charge transfer coefficient, dimensionless
  *: so-called anodic charge transfer coefficient, dimensionless
  * : activation overpotential (defined as ).
  The right hand figure shows plots valid for .