Calories to Joules
Convert cal 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 cal equals approximately 4.184 J.
How to use the Calories 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 cal equals approximately 4.184 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 cal to J conversions
| cal | J |
|---|---|
| 1 cal | 4.184 J |
| 2 cal | 8.368 J |
| 5 cal | 20.92 J |
| 10 cal | 41.84 J |
| 20 cal | 83.68 J |
| 50 cal | 209.2 J |
Example
For example, entering 1 cal gives approximately 4.184 J using the rule above. Change the input to test your own value.
Frequently asked questions
The Calories to Joules converts a value from cal 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 cal equals approximately 4.184 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.