The calorie is a unit of energy defined as the amount of heat needed to raise the temperature of a quantity of water by one degree Celsius. For historical reasons, two main definitions of calorie are in wide use.

What is a calorie easy definition?

1 : a unit for measuring heat equal to the amount of heat required to raise the temperature of one gram of water one degree Celsius. 2 : a unit of heat used to indicate the amount of energy foods produce in the human body that is equal to 1000 calories.

What is the definition of calorie in food?

When people talk about the calories in food, what do they mean? A calorie is a unit of measurement — but it doesn't measure weight or length. A calorie is a unit of energy. When you hear something contains 100 calories, it's a way of describing how much energy your body could get from eating or drinking it.