What is a calorie?

What is a calorie? A calorie is a unit used to measure heat. 

Definition of calorie: 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.

What is a Calorie?

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

Recent lesson

  1. Law of Reflection

    Mar 16, 17 03:15 PM

    Great lesson about the law of reflection. Crystal clear explanation

    Read More

Enter Your E-mail Address
Enter Your First Name (optional)

Don't worry — your e-mail address is totally secure.
I promise to use it only to send you Physics lessons.

New! Comments

Do you like the physics lessons on this site? Have your say about what you just read! Leave me a comment in the box below. Please share the lessons with your friends as well!