Calories (cal) to kilojoules (kJ), energy conversion calculator and how to convert.
Select calorie unit type, enter the energy in calories and press the Convert button:
Small & large calories
Small calorie (cal) is the energy needed to increase 1 gram of water by 1°C at a pressure of 1 atmosphere.
Large calorie (Cal) is the energy needed to increase 1 kg of water by 1°C at a pressure of 1 atmosphere.
Large calorie is also called food calorie and is used as a unit of food energy.
Thermochemical calories to kJ
1 calth = 0.004184 kJ
1 kJ = 239.005736 calth
The energy in kilojoules E(kJ) is equal to the energy in thermochemical calories E(calth) divided by 239.005736:
E(kJ) = E(calth) / 239.005736
Convert 300 calth to kilojoules.
E(kJ) = 300calth / 239.005736 = 1.2552 kJ
15°C calories to kJ
1 cal15 = 0.0041855 kJ
1 kJ = 238.9201 cal15
The energy in kilojoules E(kJ) is equal to the energy in 15°C calories E(cal15) divided by 238.9201:
E(kJ) = E(cal15) / 238.9201
Convert 300 cal15 to kilojoules.
E(kJ) = 300cal15 / 238.9201 = 1.25565 kJ
Large/food calories to kJ
1 Cal = 4.184 kJ
1 kJ = 0.239 Cal
The energy in kilojoules E(kJ) is equal to 4184 times the energy in large/food calories E(Cal):
E(kJ) = 4.184 × E(calth)
Convert 0.3 Cal to kilojoules.
E(kJ) = 4.184 × 0.3 Cal = 1.2552 kJ