1.3a The Calorie - Another Unit of Energy
One calorie is defined as the amount of heat required to raise the temperature of one gram of water by one degree Celsius (1°C).
A dietary calorie, written with a big C (Calorie, not calorie) is actually a kilocalorie, or 1000 calories.
To convert between joules and calories, use the following conversion factors:
1 J = 0.2390 cal 1 cal = 4.184 J