What is a calorie? A calorie is a unit used to measure heat. By definition, 1 calorie is the amount of heat required to raise the temperature of 1 gram of water by 1 degree Celsius or 33.8 Fahrenheit.
To
help you visualize how big is 1 gram of water, take 1 liter of water
and make 1000 portions with it. This may take a long time.
1 portion is 1 gram of water. If you put this in a teaspoon, it will occupy one-fifth of the space in that teaspoon.
1 kilogram = 1000 grams
1000 grams of water = 1 liter of water
1 kilogram of water = 1 liter of water
1 kilocalorie = 1000 calories
1000 calories means that 1000 grams or 1 kilogram of water raised to 1 degree Celsius.
Therefore, 1 kilocalorie is the amount of heat required to raise 1 kilogram or 1 liter of water by 1 degree Celsius.
Notice this time that Calorie starts with a capital letter. Both are units of energy. However, there is a difference between calorie and Calorie.
Calorie is the unit used by the food industry to measure the energy released as heat in your body when you consume food.
1 Calorie = 1 kilocalorie = 1000 calories
Be careful not to confuse 1 Calorie with 1 calorie. Again they are not the same.
Since heat is a form of energy, we can also use joules to measure heat
1 calorie = 4.184 joules
1 Calorie = 1000 × 1 calorie
1 Calorie = 1000 × 4.184 joules
1 Calorie = 4184 joules