Mega-electron volts to megajoules converter above calculates how many megajoules are in 'X' mega-electron volts (where 'X' is the number of mega-electron volts to convert to megajoules). In order to convert a value from mega-electron volts to megajoules (from MeV to MJ) simply type the number of MeV to be converted to MJ and then click on the 'convert' button.