cal to kJ Converter - Calorie to Kilojoule
Calorie (cal) to Kilojoule (kJ)
Direct answer
1 cal = 0.004184 kJ
kJ = cal × 0.004184
Converter
Conversion formula
kJ = cal × 0.004184
cal = kJ × 239.005736138
Example: 10 cal = 10 × 0.004184 = 0.04184 kJ.
Common conversion table
| cal | kJ |
|---|---|
| 1 cal | 0.004184 kJ |
| 2 cal | 0.008368 kJ |
| 5 cal | 0.02092 kJ |
| 10 cal | 0.04184 kJ |
| 20 cal | 0.08368 kJ |
| 50 cal | 0.2092 kJ |
| 100 cal | 0.4184 kJ |
| 1,000 cal | 4.184 kJ |
Conversion derivation
Express both cal and kJ in the same base unit J (joule), then cancel the shared base unit.
- 1
Rewrite cal in the base unit
- 2
Rewrite kJ in the base unit
- 3
Forward conversion
- 4
Reverse conversion
AI explanation for this conversion
This pre-generated explanation is schema-checked. Numeric results still come from the page formula and calculator.
Explanation of the Calorie to Kilojoule Conversion Factor
The conversion factor from calories (cal) to kilojoules (kJ) is based on expressing both units in terms of the joule (J), the SI base unit for energy. By defining 1 cal as 4.184 J and 1 kJ as 1,000 J, the factor is derived through division.
Definition
The calorie (cal) is a unit of energy, and the kilojoule (kJ) is a metric unit equal to 1,000 joules. The conversion links these two energy measures.
Principle
The principle is to express both the calorie and kilojoule in the common base unit, the joule. The factor results from dividing the joule equivalent of a calorie by the joule equivalent of a kilojoule.
Assumptions
- The conversion uses the definition that 1 calorie (cal) equals exactly 4.184 joules.
- The kilojoule (kJ) is defined as exactly 1,000 joules.
Cautions
- This explanation uses the standard thermochemical calorie (cal). Nutritional labels often use the large calorie (Cal, kcal), which is 1,000 times larger.
- The derived factor is exact based on the provided definitions. Rounding should be applied to the final result as needed.
FAQ
How many kJ are in 1 cal?
1 cal = 0.004184 kJ.
How many kJ are in 10 cal?
10 cal = 0.04184 kJ.
How many kJ are in 100 cal?
100 cal = 0.4184 kJ.
What is the formula to convert cal to kJ?
Use kJ = cal × 0.004184.
How many cal are in 1 kJ?
1 kJ = 239.005736138 cal.
What should I check when converting cal to kJ?
Use the conversion factor and round the result to the precision required by your calculation.