# Relationship between joules and kilojoules

### What's the difference between a calorie and a kilojoule | Queensland Health

Joe Rovito, I scale my dough in grams, and know the difference between mass and weight. Answered . The conversion from calorie to joule is 1 kcal = kJ. A calorie is a unit of measure of the energy required to raise the temperature of 1 gram of water by 1 degree C. A joule is a unit of electrical energy, commonly. Kilojoules (kJ), and calories (kcal), are both units that measure energy. Our program uses kcal to measure your energy intake and energy used. If you would .

Why are we still talking about them?

### Joule - Wikipedia

Essentially, the difference between calories and kilojoules is terminology - they're two different ways of measuring the energy contained in food and the energy we expend. You can convert calories to kilojoules by multiplying the calories by 4.

Unlike the inch or the mile, which have fallen out of popular usage in Australia, the calorie remains pretty current when it comes to the way people think about food.

The science community may have swapped over to kilojoules, but the calorie is everywhere when consumers start looking at weight loss, dieting, and apps for measuring their daily energy consumption.

The resistance to update is understandable: Old terminology tends to linger, particularly when one of the countries that stuck with the older measures is the United States of America. That said, if you are interested in tracking the energy levels in your food, it might be worth switching your thinking over to kilojoules for the same reason it's easier to think in kilometres when travel long-distances in Australia - all the official signs and food packaging use those measurements, and you don't have to rely on someone translating them for you.

Regardless of the term you use, here's what really matters Whether you use calories or kilojoules, what really matters is how they're related to achieving and maintaining a healthy weight.

You naturally take in energy from the food that you eat. You naturally burn off energy through the process of living your life, with everything from sleeping to lifting weights taking something from your energy reserves. Your exact daily energy requirements will vary based on your age, height, gender, and general level of physically activity, but weight gain tends to happen when you consume more energy than you expend.

If you're curious about what your daily energy requirements are, you can use this calculator to find out. Learning your energy requirements is your first step, but your second is learning to recognise that not all kilojoules are created equal.

The transfer of energy due to temperature differences is called heat. For example, if you hold an ice cube in your hand, the ice cube slowly melts as energy in the form of heat is transferred from your hand to the ice. As your hand loses energy, it starts to feel cold. Because of their interrelationships, energy, work, and heat have the same units. The SI unit of energy, work, and heat is the joule J.

A joule is a tiny amount of energy. Many processes occur with energy changes in thousands of joules, so the kilojoule kJ is also common.

## Convert J to kJ

Another unit of energy, used widely in the health professions and everyday life, is the calorie cal. Although the joule is the proper SI unit for energy, we will use the calorie or the kilocalorie or Calorie in this chapter because they are widely used by health professionals. The calorie is used in nutrition to express the energy content of foods. However, because a calorie is a rather small quantity, nutritional energies are usually expressed in kilocalories kcalalso called Calories capitalized; Cal.

For example, a candy bar may provide Cal nutritional calories of energy, which is equal tocal. A sample nutrition facts label, with instructions from the U.