Kilocalorie to Kilojoule Converter
Enter the value that you want to convert kilocalorie (kcal) to kilojoule (kJ) or kilojoule to kilocalorie.Also written as KCAL to KJ conversion.
1 kilocalorie = 4.1868000 kilojoule
Formula: kilojoule = kilocalorie value × 4.1868000
KCAL to KJ — kilocalorie to kilojoule
10 kilocalorie = 41.86800 kilojoule
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Kilocalorie to Kilojoule: The Essentials
What is Kilocalorie?
Kilocalorie (kcal) is a unit of energy measurement. 1 kilocalorie is equal to 4.1868000 kilojoule.
About the Kilojoule
Kilojoule (kJ) is a unit of energy measurement. 1 kilojoule is equal to 0.2388459 kilocalorie.
Energy Units in Different Fields
Energy measurement units reflect their historical origins across different industries. Electrical engineers use kilowatt-hours, nutritionists use calories, physicists use joules, heating engineers use BTUs, and the petroleum industry uses barrels of oil equivalent. Converting between these units is essential for energy auditing, comparing fuel sources, sizing HVAC systems, and understanding electricity bills relative to gas consumption.
kilocalorie to kilojoule metric conversion table
| 0.01 kcal | = | 0.04187 kJ |
| 0.1 kcal | = | 0.41868 kJ |
| 1 kcal | = | 4.18680 kJ |
| 2 kcal | = | 8.37360 kJ |
| 3 kcal | = | 12.56040 kJ |
| 4 kcal | = | 16.74720 kJ |
| 5 kcal | = | 20.93400 kJ |
| 6 kcal | = | 25.12080 kJ |
| 7 kcal | = | 29.30760 kJ |
| 8 kcal | = | 33.49440 kJ |
| 9 kcal | = | 37.68120 kJ |
| 10 kcal | = | 41.86800 kJ |
| 11 kcal | = | 46.05480 kJ |
| 12 kcal | = | 50.24160 kJ |
| 13 kcal | = | 54.42840 kJ |
| 14 kcal | = | 58.61520 kJ |
| 15 kcal | = | 62.80200 kJ |
| 16 kcal | = | 66.98880 kJ |
| 17 kcal | = | 71.17560 kJ |
| 18 kcal | = | 75.36240 kJ |
| 19 kcal | = | 79.54920 kJ |
| 20 kcal | = | 83.73600 kJ |
| 30 kcal | = | 125.60400 kJ |
| 40 kcal | = | 167.47200 kJ |
| 50 kcal | = | 209.34000 kJ |
| 60 kcal | = | 251.20800 kJ |
| 70 kcal | = | 293.07600 kJ |
| 80 kcal | = | 334.94400 kJ |
| 90 kcal | = | 376.81200 kJ |
| 100 kcal | = | 418.68000 kJ |
| 200 kcal | = | 837.36000 kJ |
| 300 kcal | = | 1256.04000 kJ |
| 400 kcal | = | 1674.72000 kJ |
| 500 kcal | = | 2093.40000 kJ |
| 600 kcal | = | 2512.08000 kJ |
| 700 kcal | = | 2930.76000 kJ |
| 800 kcal | = | 3349.44000 kJ |
| 900 kcal | = | 3768.12000 kJ |
| 1000 kcal | = | 4186.80000 kJ |
How to Convert KCAL to KJ (Kilocalorie to Kilojoule)?
We can convert kilocalorie to kilojoule by using an example.
Example:
Convert 20 Kilocalorie to Kilojoule?
We know 1 Kilocalorie = 4.1868000 kilojoule; 1 Kilojoule = 0.2388459 kilocalorie.
20 kilocalorie = ___kJ
20 × 4.1868000 = 83.73600 kJ (we know 1 kilocalorie = 4.1868000 kilojoule)
Answer:
20 kilocalorie = 83.73600 kilojoule
How to Convert Kilocalories to Kilojoules (Step-by-Step)
Converting kcal to kJ is needed when comparing US nutrition information with international food labels. This conversion is especially useful for travelers, imported food products, and scientific research that requires SI units.
- Identify the Calorie (kcal) value from the US nutrition facts panel.
- Multiply the kcal value by 4.1868 to get kilojoules.
- Round to appropriate precision (whole numbers for food labels).
Common kcal to kJ Conversions (Nutrition Comparison)
Converting popular US food Calorie counts to kJ for international label comparison.
| Kilocalorie | Kilojoule |
|---|---|
| 100 kcal | 418.7 kJ |
| 250 kcal | 1046.7 kJ |
| 500 kcal | 2093.4 kJ |
| 800 kcal | 3349.4 kJ |
| 2000 kcal | 8373.6 kJ |
| 2500 kcal | 10467.0 kJ |
| 3000 kcal | 12560.4 kJ |
Solved Examples: kcal to kJ Conversion
Question 1: A US granola bar has 190 Calories. What would the label show in kJ for export to Europe?
Solution:
Start with 190 kcal.
Multiply by 4.1868: 190 × 4.1868 = 795.5 kJ.
Round for the label: 796 kJ.
Answer: 190 kcal = 796 kJ
Question 2: Your daily intake was 2200 Calories. Express this in kJ.
Solution:
Start with 2200 kcal.
Multiply by 4.1868: 2200 × 4.1868 = 9211.0 kJ.
This is slightly above the 8700 kJ Australian guideline.
Answer: 2200 kcal = 9211 kJ
Question 3: A recipe website lists a dish at 650 Calories per serving. Convert to kJ.
Solution:
Start with 650 kcal.
Multiply by 4.1868: 650 × 4.1868 = 2721.4 kJ.
Round: ≈ 2721 kJ.
Answer: 650 kcal ≈ 2721 kJ
Practice: kcal to kJ Conversions
Try solving these on your own to test your understanding:
- Convert 350 kcal to kJ. (Answer: ≈ 1465.4 kJ)
- A smoothie has 280 Calories. What is this in kJ? (Answer: ≈ 1172.3 kJ)
- Convert 1500 kcal to kJ. (Answer: ≈ 6280.2 kJ)
- An energy drink has 110 Calories. Express in kJ. (Answer: ≈ 460.5 kJ)
- Your breakfast totals 450 kcal. How many kJ? (Answer: ≈ 1884.1 kJ)
International Food Labeling Requirements
EU Regulation 1169/2011 requires energy to be expressed in both kJ and kcal on food labels, with kJ listed first. Australia and New Zealand (under FSANZ) require kJ as the primary unit. The US FDA requires Calories only. When exporting food products, manufacturers must convert kcal to kJ for compliance with international labeling laws.
kcal to kJ in Exercise Science
Exercise physiologists often work in kJ when publishing in international journals. Running burns approximately 4.2 kJ per kilogram per kilometer (1 kcal/kg/km). A 70 kg person running 5 km expends about 1470 kJ (351 kcal). Cycling is more efficient at roughly 1.0–1.5 kJ/kg/km depending on speed and terrain.
Why the Factor Is Exactly 4.1868
The thermochemical calorie was originally defined as the heat needed to raise 1 gram of water by 1°C. However, this varies with temperature. The International Table calorie (used in nutrition) was standardized at exactly 4.1868 joules by the Fifth International Conference on Properties of Steam (1956). This is the factor used on all modern food labels.
Key Takeaways
- Multiply kcal by 4.1868 to get kJ.
- Quick estimate: multiply Calories by 4.2.
- 2000 kcal (US daily value) ≈ 8374 kJ.
- EU labels must show both kJ and kcal; kJ is listed first.
- The conversion factor 4.1868 is an exact defined value (International Table calorie).
- Useful for comparing US foods with international nutrition databases.
Kilocalorie to Kilojoule Conversion Formula
kilojoule = kilocalorie × 4.1868000
1 kilocalorie = 4.1868000 kilojoule
1 kilojoule = 0.2388459 kilocalorie
Reverse: kilocalorie = kilojoule × 0.2388459
Frequently Asked Questions
How many kilojoule are in 1 kilocalorie?
There are 4.1868000 kilojoule in 1 kilocalorie. To convert kilocalorie to kilojoule, multiply the value by 4.1868000.
How do I convert kilocalorie to kilojoule?
Multiply your kilocalorie value by 4.1868000 to get the equivalent in kilojoule. For example, 5 kilocalorie = 5 × 4.1868000 = 20.93400 kilojoule.
How do I convert kilojoule to kilocalorie?
Multiply your kilojoule value by 0.2388459 to get the equivalent in kilocalorie. Alternatively, divide by 4.1868000.
What is 10 kilocalorie in kilojoule?
10 kilocalorie is equal to 41.86800 kilojoule.
What is 100 kilocalorie in kilojoule?
100 kilocalorie is equal to 418.68000 kilojoule.