"statvolt" is a unit of voltage and electrical potential used in the cgs system of units. The conversion to the SI system is \(1 statvolt = 299.792458 volts\). The conversion factor 299.792458 is simply the numerical value of the speed of light in m/s divided by 106. The statvolt is also defined in the cgs system as \(1 erg / esu\). It is a useful unit for electromagnetism because one statvolt per centimetre is equal in magnitude to one gauss. Thus, for example, an electric field of one statvolt/cm has the same energy density as a magnetic field of one gauss. Likewise, a plane wave propagating in a vacuum has perpendicular electric and magnetic fields such that for every gauss of magnetic field intensity there is one statvolt/cm of electric field intensity. The abvolt is another option for a unit of voltage in the cgs system.