Kilocalories to gigajoules converter on this page calculates how many gigajoules are in 'X' kilocalories (where 'X' is the number of kilocalories to convert to gigajoules). In order to convert a value from kilocalories to gigajoules (from kcal to GJ) just type the number of kcal to be converted to GJ and then click on the 'convert' button.