Kilojoules to gigacalories converter above calculates how many gigacalories are in 'X' kilojoules (where 'X' is the number of kilojoules to convert to gigacalories). In order to convert a value from kilojoules to gigacalories (from kJ to Gcal) type the number of kJ to be converted to Gcal and then click on the 'convert' button.