Written by Gavin van De Walle, MS, RD — median reviewed by Kim climbed RDN, CDCES, CNSC, LD, Nutrition — to update on in march 8, 2021

Calories space a measure up of energy. They describe the lot of power in foods and also beverages, or the lot of power you burn exercising.

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Depending on wherein you live, power may additionally be measure in kilocalories (kcal) and kilojoules (kJ).

This can produce confusion, especially if you counting calories or to compare the calorie contents of assorted foods and drinks.

This write-up explains what calories are and how lock compare with kcal and kJ as well as how to convert in between the two.

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When it involves calories, they may be “small” or “large.”

If the “c” in calorie is uppercase, it shows a large calorie, and also if it’s lowercase, it shows a tiny calorie.

A large calorie approximates the quantity of power required come raise the temperature of 1 kg (2.2 pounds) the water by 1°C (or an increase of 1.8°F) (1).

On the other hand, a tiny calorie estimates the lot of power it takes to raise the temperature that 1 gram (0.035 ounces) of water through 1°C (or an increase of 1.8°F) (1).

By these definitions, 1 huge calorie equals 1,000 tiny calories, as 1 kg equates to 1,000 grams.

To avoid confusion between huge and small calories, it’s thought that the term kilocalorie — the prefix “kilo” definition 1,000 — was produced to refer to a large calorie (1).

However, the term tiny calorie is rarely offered today outside of physics and chemistry research.

Instead, the state calories — capitalized or not — and also kcal are offered interchangeably and also refer to the very same amount of energy in relation to food or energy shed with exercise.

Therefore, you don’t need to transform them, together 1 kilocalorie amounts to 1 calorie in nutrition.

Calories may likewise be expressed together kilojoules (kJ).

One calorie (kcal) equates to 4.18 kJ or 4,184 joules (J) (1).

To convert from calorie to kJ, multiple calorie by 4.18. Whereas to transform from kJ come calories, divide kJ through 4.18.

For example, a medium-sized banana (118 grams) offers 105 calorie (kcal) or 439 kJ (2).


When it concerns nutrition and also exercise, kilocalories (kcal) and calories same the exact same amount the energy. Calorie may also be expressed as kilojoules (kJ), v one calorie or kcal equaling 4.18 kJ.

Regulations call for that food and also beverage manufacturers display a nutrition facts label on their products. It lists, amongst other information, the quantity of energy the item has per offer or load (3).

The nutrition facts brand serves to assist inform you about the healthfulness the packaged foods and beverages, and whether castle contain ingredients the you might need to avoid because of an allergy, intolerance, or an individual preference.

Depending on whereby you live, the nutrition facts panel may express the power value the a food or beverage in calories, kcal, kJ, or a combination of them.

Below is a perform of countries and which label they use for power (4, 5, 6, 7, 8):

United States: caloriesCanada: caloriesEuropean Union (EU): kJ and also kcalAustralia and new Zealand: kJ or both kJ and kcalChina: kJ

Manufacturers recognize the number of calories a food or beverage contains based on the amount of energy-supplying nutrient it contains.

The three main energy-supplying nutrient are:

protein carbsfats

Protein and carbs each provide about 4 calorie (16.7 kJ) every gram, while fat gives 9 calories per gram (37.6 kJ) (9).

Alcohol additionally supplies 7 calories (29.3 kJ) every gram.

Manufacturers round to the nearest 1-gram increment, so if you were to quantify the number of calories or kJ from every of the macronutrients, lock may add up to it is in slightly different than the number detailed on the nutrition label (4).

See more: Dechancourtois Contribution To The Periodic Table, De Chancourtois Periodic Table

Moreover, the nutrition brand of foods items that save fiber, i m sorry is classified as a carbohydrate, may contain fewer calories than what girlfriend calculate.

This is since fiber, depending on the type, is one of two people indigestible or poorly digested, thus contributing zero or couple of calories (10).


Most packaged foods and also beverages save a nutrition brand that perform the lot of power the item contains in calories, kcal, kJ, or some combination of these.