Kilojoules (kJ) and kilocalories (kcal) are both units of energy. One calorie is defined as the energy required to increase the temperature of 1 gram of water by 1°C. Also, the conversion factor to be used for this is 1 calorie = 4.184 joules. This is the same as 1 kilocalorie = 4.184 kilojoules. To get the equivalent energy in units of kilocalories, we have the following equation:
31.39 kJ x 1 kcal/4.184 kJ = 7.5024 kcal