One calorie (cal) is equal to approximately 4.184 joules (J). This is the standard conversion used to express energy, where the calorie is defined as the amount of energy needed to raise the temperature of 1 gram of water by 1 degree Celsius at atmospheric pressure
. To summarize:
- 1 calorie (small calorie, cal) = 4.184 joules (J)
- 1 kilocalorie (kcal or Cal, often called a "food calorie") = 1000 calories = 4184 joules
This conversion is widely accepted and used in physics, chemistry, and nutrition contexts
. Thus, whenever you want to convert calories to joules, multiply the number of calories by 4.184 to get the equivalent energy in joules.
