Giga-electron volts to mega-electron volts conversion calculator shown above calculates how many mega-electron volts are in 'X' giga-electron volts (where 'X' is the number of giga-electron volts to convert to mega-electron volts). In order to convert a value from giga-electron volts to mega-electron volts (from GeV to MeV) type the number of GeV to be converted to MeV and then click on the 'convert' button.