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Kilocalories (kcal) and kilojoules (kJ) are units of energy commonly used to measure the amount of energy provided by food and used by the body. Both units are used to quantify the energy content of foods and beverages.
Kilocalories (kcal)
The kilocalorie is often referred to simply as a “calorie” in everyday language. It is a unit of energy commonly used to express the amount of energy that food provides when metabolized by the body.
One kilocalorie is equal to the amount of energy required to raise the temperature of 1 kilogram of water by 1 degree Celsius. In nutritional contexts, the calorie values you see on food labels are usually in kilocalories (kcal).
Kilojoules (kJ)
The kilojoule is the SI unit of energy and is commonly used in scientific and international contexts. One kilojoule is equal to 0.239 kilocalories. It’s important to note that while kilocalories are the more commonly used unit of energy in nutrition labeling, kilojoules are used in many other fields, such as physics and engineering.
How to convert from kcal to kilojoules
To convert from kilocalories (kcal) to kilojoules (kJ), you can use the conversion factor: 1 kcal = 4.184 kJ. This means that 1 kilocalorie is equal to 4.184 kilojoules.
To convert a value from kilocalories to kilojoules, you simply multiply the number of kilocalories by the conversion factor:
Energy in kilojoules (kJ) = Energy in kilocalories (kcal) × 4.184
For example, let’s say you have a food item with an energy content of 200 kilocalories (kcal). To convert this to kilojoules:
Energy in kJ = 200 kcal × 4.184 kJ/kcal = 836.8 kJ
So, 200 kilocalories is equal to approximately 836.8 kilojoules.
kcal to kilojoules Conversion Table
| Kilocalories | Kilojoules |
| 1 kcal | 4.184 kJ |
| 2 kcal | 8.368 kJ |
| 3 kcal | 12.55 kJ |
| 4 kcal | 16.74 kJ |
| 5 kcal | 20.92 kJ |
| 6 kcal | 25.1 kJ |
| 7 kcal | 29.29 kJ |
| 8 kcal | 33.47 kJ |
| 9 kcal | 37.66 kJ |
| 10 kcal | 41.84 kJ |
| 11 kcal | 46.02 kJ |
| 12 kcal | 50.21 kJ |
| 13 kcal | 54.39 kJ |
| 14 kcal | 58.58 kJ |
| 15 kcal | 62.76 kJ |
| 16 kcal | 66.94 kJ |
| 17 kcal | 71.13 kJ |
| 18 kcal | 75.31 kJ |
| 19 kcal | 79.5 kJ |
| 20 kcal | 83.68 kJ |
| 21 kcal | 87.86 kJ |
| 22 kcal | 92.05 kJ |
| 23 kcal | 96.23 kJ |
| 24 kcal | 100.42 kJ |
| 25 kcal | 104.6 kJ |
| 26 kcal | 108.78 kJ |
| 27 kcal | 112.97 kJ |
| 28 kcal | 117.15 kJ |
| 29 kcal | 121.34 kJ |
| 30 kcal | 125.52 kJ |
| 31 kcal | 129.7 kJ |
| 32 kcal | 133.89 kJ |
| 33 kcal | 138.07 kJ |
| 34 kcal | 142.26 kJ |
| 35 kcal | 146.44 kJ |
| 36 kcal | 150.62 kJ |
| 37 kcal | 154.81 kJ |
| 38 kcal | 158.99 kJ |
| 39 kcal | 163.18 kJ |
| 40 kcal | 167.36 kJ |
FAQs on kcal to kilojoules conversion
Is 1 kcal equal to 1 kJ?
No, 1 kcal is not equal to 1 kJ. 1 kcal (kilocalorie) is equivalent to 4.184 kJ (kilojoules).
How do you go from kcal to kJ?
To convert from kcal to kJ, multiply the number of kilocalories by the conversion factor 4.184. Energy in joules (J) = Energy in kilocalories (kcal) × 4.184.
How many kcals is a kJ?
1 kJ (kilojoule) is equal to approximately 0.239 kcal (kilocalories).
How many kcal is 1 kg?
1 kg (kilogram) is a measure of mass, not energy, so it cannot be directly converted to kcal or any other energy unit.
Does 1 calorie equal 1 kcal?
Yes, in the context of nutrition and dietary discussions, 1 calorie is equivalent to 1 kcal (kilocalorie).
What is the unit of 1 kcal?
The unit of 1 kcal is kilocalorie. It's often referred to as calorie in everyday language when discussing food energy.
Is 1 kcal 4.2 J?
No, 1 kcal is not exactly 4.2 J. 1 kcal is equal to 4.184 J.
How do you go from kcal to kJ?
To convert from kcal to kJ, multiply the number of kilocalories by the conversion factor 4.184. Energy in joules (J) = Energy in kilocalories (kcal) × 4.184.
