kcal to J Converter - Kilocalorie to Joule
Kilocalorie (kcal) to Joule (J)
Direct answer
1 kcal = 4,184 J
J = kcal × 4,184
Converter
Conversion formula
J = kcal × 4,184
kcal = J × 0.000239005736
Example: 10 kcal = 10 × 4,184 = 41,840 J.
Common conversion table
| kcal | J |
|---|---|
| 1 kcal | 4,184 J |
| 2 kcal | 8,368 J |
| 5 kcal | 20,920 J |
| 10 kcal | 41,840 J |
| 20 kcal | 83,680 J |
| 50 kcal | 209,200 J |
| 100 kcal | 418,400 J |
| 1,000 kcal | 4,184,000 J |
Conversion derivation
Express both kcal and J in the same base unit J (joule), then cancel the shared base unit.
- 1
Rewrite kcal in the base unit
- 2
Rewrite J 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.
Why the kcal to J conversion factor holds
The conversion factor of 4,184 joules per kilocalorie is based on the defined equivalence between these energy units. It allows direct multiplication to convert energy measured in kilocalories to energy measured in joules.
Definition
A kilocalorie (kcal) is a unit of energy defined as 4,184 joules (J). The joule is the SI derived unit of energy.
Principle
The conversion is a direct application of the definition. Since 1 kcal is defined to equal 4,184 J, any energy value in kcal can be converted to J by multiplying by 4,184.
Assumptions
- The conversion uses the defined relationship: 1 kcal = 4,184 J.
- This is the standard 'thermochemical calorie' definition commonly used in nutrition and science.
Cautions
- The 'calorie' has multiple definitions (e.g., thermochemical, International Table). This conversion factor is specific to the thermochemical definition.
- Precision of the result depends on the precision of the input value and the required rounding.
FAQ
How many J are in 1 kcal?
1 kcal = 4,184 J.
How many J are in 10 kcal?
10 kcal = 41,840 J.
How many J are in 100 kcal?
100 kcal = 418,400 J.
What is the formula to convert kcal to J?
Use J = kcal × 4,184.
How many kcal are in 1 J?
1 J = 0.000239005736 kcal.
What should I check when converting kcal to J?
Use the conversion factor and round the result to the precision required by your calculation.