Calories to Kilojoules (kJ) conversion

Calories (cal) to kilojoules (kJ), energy conversion calculator and how to convert.

Calories to kilojoules conversion calculator

Select calorie unit type, enter the energy in calories and press the Convert button:

 Select calorie unit type: Small thermochemical calories Small 15°C calories Large/food calories Enter energy in calories: Energy result in kilojoules: kJ

kJ to calories conversion ►

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.

How to convert from calories to kilojoules

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

Example

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

Example

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)

Example

Convert 0.3 Cal to kilojoules.

E(kJ) = 4.184 × 0.3 Cal = 1.2552 kJ

kJ to calories conversion ►