Kilocalories to Joules
Convert kcal to J quickly with this free online calculator. The page explains the conversion rule, gives practical examples and provides a quick reference table.
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CONVERTED RESULT—
Decimal places
CONVERSION RULE
1 kcal equals approximately 4184 J.
How to use the Kilocalories to Joules
- Enter the number you want to convert.
- Confirm the source unit shown beside the input.
- Choose decimal precision if you need more or less detail.
- Read the converted result.
- Copy the result when you need to use it elsewhere.
How the conversion works
1 kcal equals approximately 4184 J.
For a simple fixed-factor conversion, the calculator multiplies the entered value by the stated factor. Temperature scales and certain specialized tools use their specific mathematical relationship instead.
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Common kcal to J conversions
| 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 |
Example
For example, entering 1 kcal gives approximately 4,184 J using the rule above. Change the input to test your own value.
Frequently asked questions
The Kilocalories to Joules converts a value from kcal to J using the conversion relationship described on this page.
Enter your value, review the source and destination units, choose the decimal precision and read or copy the result.
1 kcal equals approximately 4184 J.
Use enough precision for your purpose. Everyday estimates usually need fewer decimal places; technical work may require more.
It can be a useful reference calculation, but safety-critical, regulated, contractual or specialized work should be verified against the applicable authoritative standard.
Accuracy note: This calculator is a practical reference. For regulated, safety-critical or specialized work, verify the result against the applicable standard.
Page reviewed: August 24, 2026.