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