How to convert calories (cal) to kilocalories (kcal).
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.
cal to kcal - small calories to small kilocalories
1 kcal = 1000 cal
The energy in small kilocalories (kcal) is equal to the energy in small calories (cal) divided by 1000:
E(kcal) = E(cal) / 1000
Example
Convert 6000cal to small kcal:
E(kcal) = 6000cal / 1000 = 6 kcal
Cal to kcal - large calories to small kilocalories
1 kcal = 1 Cal
The energy in small kilocalories (kcal) is equal to the energy in large calories (Cal):
E(kcal) = E(Cal)
Example
Convert 6Cal to kcal:
E(kcal) = 6Cal = 6kcal