Millijoules to kilo-electron volts conversion calculator above calculates how many kilo-electron volts are in 'X' millijoules (where 'X' is the number of millijoules to convert to kilo-electron volts). In order to convert a value from millijoules to kilo-electron volts (from mJ to keV) simply type the number of mJ to be converted to keV and then click on the 'convert' button.