Calorie to Joule Converter
One Calorie equals 4.184 Joule (1 cal = 4.184 J). Multiply a Calorie value by 4.184 to get the equivalent in Joule. Use the calculator above for instant results, or follow the formula, worked examples, and reference table below.
Formula
J = cal × 4.184
Multiply the Calorie value by 4.184 to get the equivalent value in Joule.
Example Conversions
1 Calorie (cal)
4.184 Joule (J)
5 Calorie (cal)
20.92 Joule (J)
10 Calorie (cal)
41.84 Joule (J)
25 Calorie (cal)
104.6 Joule (J)
100 Calorie (cal)
418.4 Joule (J)
Conversion Table
| Calorie (cal) | Joule (J) |
|---|---|
| 0.1 | 0.4184 |
| 0.5 | 2.092 |
| 1 | 4.184 |
| 2 | 8.368 |
| 5 | 20.92 |
| 10 | 41.84 |
| 25 | 104.6 |
| 50 | 209.2 |
| 100 | 418.4 |
| 250 | 1046 |
| 500 | 2092 |
| 1000 | 4184 |
How to Convert Manually
Use these steps to convert Calorie values to Joule without the calculator.
- Write down the value in Calorie (cal) that you want to convert.
- Multiply that value by 4.184.
- For example, 10 Calorie × 4.184 = 41.84 Joule.
- Label the result as Joule (J).
Relative Size Comparison
This chart shows the visual difference in size between exactly one Calorie and one Joule.
About Calorie and Joule
The calorie (small calorie) is exactly 4.184 joules — the thermochemical convention, originally the heat to warm one gram of water by 1 °C. Chemistry uses it; food 'Calories' are actually kilocalories. The joule is the SI derived unit of energy — the work done by a force of one newton over one meter. Physics, chemistry, and food labeling outside the US build on it. One Calorie equals 4.184 Joule (1 cal = 4.184 J). Calorie to Joule conversion comes up most often in chemistry heat calculations and in scientific literature, typically when figures need restating for physics and engineering calculations.
Precision and Rounding: Energy factors mix exact definitions (1 kWh = 3,600,000 J; 1 cal = 4.184 J thermochemical) with measured conventions (1 BTU ≈ 1,055.056 J). Nutrition and utility bills round to whole units; engineering heat calculations should keep the full factor until the final step.
Conversion factors per NIST Special Publication 811 and the BIPM SI Brochure (9th edition) (reference).
Worked Example
15 Calorie equals 62.76 Joule.
15 cal × 4.184 = 62.76 J
FAQ
How do I convert Calorie to Joule?
Multiply the Calorie value by 4.184 to get the equivalent value in Joule.
What is the formula for Calorie to Joule?
The formula is J = cal × 4.184.
How many Joule are in 1 Calorie?
1 Calorie equals 4.184 Joule.
Can I convert Joule back to Calorie?
Yes. 1 Joule equals 0.2390057361 Calorie, and the related converter can reverse the calculation.
What are common names for Calorie and Joule?
Calorie is shown as cal and may also be searched as calorie, calories, small calorie. Joule is shown as J and may also be searched as joule, joules.
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