1 joule equals approximately 0.2390 calories. This means when you convert 1 joule of energy, you get about 0.2390 calories of energy.
The joule and calorie both measure energy, but they belong to different unit systems. Joule is part of the SI system, while calorie is part of the metric system, mainly used in chemistry and food energy. The conversion involves multiplying joules by a fixed factor to get calories.
Conversion Tool
Result in calorie:
Conversion Formula
The formula to convert joule to calorie is:
calorie = joule × 0.239005736
Why this works? Because 1 calorie is defined as exactly 4.184 joules. So to find how many calories correspond to 1 joule, you divide 1 by 4.184 (1 ÷ 4.184 ≈ 0.2390). Thus, multiplying any energy value in joules by 0.2390 gives its equivalent in calories.
Example:
- Convert 10 joules to calories:
- 10 joules × 0.239005736 = 2.3901 calories
Conversion Example
- Convert 5 joules to calories:
- Multiply 5 by 0.239005736
- 5 × 0.239005736 = 1.1950 calories
- So, 5 joules equal 1.1950 calories.
- Convert 12.5 joules to calories:
- 12.5 × 0.239005736 = 2.9876 calories
- Therefore, 12.5 joules is about 2.9876 calories.
- Convert 0.75 joules to calories:
- 0.75 × 0.239005736 = 0.1793 calories
- Hence, 0.75 joules equals approximately 0.1793 calories.
- Convert 20 joules to calories:
- 20 × 0.239005736 = 4.7801 calories
- So, 20 joules correspond to 4.7801 calories.
Conversion Chart
| Joule (J) | Calorie (cal) |
|---|---|
| -24.0 | -24.0 × 0.239005736 = -5.7361 |
| -22.0 | -5.2581 |
| -20.0 | -4.7801 |
| -18.0 | -4.3021 |
| -16.0 | -3.8241 |
| -14.0 | -3.3461 |
| -12.0 | -2.8681 |
| -10.0 | -2.3901 |
| -8.0 | -1.9120 |
| -6.0 | -1.4340 |
| -4.0 | -0.9560 |
| -2.0 | -0.4780 |
| 0.0 | 0.0000 |
| 2.0 | 0.4780 |
| 4.0 | 0.9560 |
| 6.0 | 1.4340 |
| 8.0 | 1.9120 |
| 10.0 | 2.3901 |
| 12.0 | 2.8681 |
| 14.0 | 3.3461 |
| 16.0 | 3.8241 |
| 18.0 | 4.3021 |
| 20.0 | 4.7801 |
| 22.0 | 5.2581 |
| 24.0 | 5.7361 |
| 26.0 | 6.2141 |
The chart above shows joule values in the left column and their calorie equivalents on the right. To use it, find the joule value closest to yours, then read across to see the calorie equivalent. Negative values mean energy loss or decrease.
Related Conversion Questions
- How many calories are in 1 joule of energy?
- What is the formula to convert 1 joule to calorie?
- Is 1 joule bigger or smaller than 1 calorie?
- How do I change 1 joule into calories using a calculator?
- Can 1 joule equal exactly 0.239 calories or is it approximate?
- What’s the difference between joule and calorie when converting 1 unit?
- How much energy in calories does 1 joule represent?
Conversion Definitions
Joule: A joule is the SI unit for energy, equal to the work done when applying a force of one newton over a distance of one meter. It measures energy transferred or converted, such as heat, electricity, or mechanical work, widely used in physics and engineering fields.
Calorie: A calorie is a unit of energy, mostly used to quantify heat energy in chemistry and food science. One calorie is the amount of energy needed to raise the temperature of 1 gram of water by 1 degree Celsius, according to the metric system.
Conversion FAQs
Why does 1 joule convert to approximately 0.239 calories?
Because 1 calorie equals exactly 4.184 joules, dividing 1 joule by 4.184 gives the calorie equivalent. This fixed ratio exists due to how the calorie was defined in relation to water’s heating properties, making the conversion constant.
Can I convert joules to food calories using the same formula?
No, food calories (kilocalories) differ from scientific calories by a factor of 1000. To convert joules to food calories, divide joules by 4184 instead of 4.184. The formula here applies only to scientific small calories.
What causes negative joule values in the conversion chart?
Negative joule values represent energy loss or removal in a system. When you convert negative joules to calories, the result also turns negative, indicating the direction of energy flow opposite to gain.
Is the joule to calorie conversion affected by temperature?
The conversion factor itself isn’t temperature dependent, because both units relate to energy. However, calories originated from water heating, so temperature influences calorie definitions historically, but the exact value 4.184 joules per calorie is fixed.
Does the conversion tool handle decimal inputs properly?
Yes, the tool allows any numeric input including decimals and negative numbers, converting them using the formula accurately and displaying results rounded to four decimal places.
Last Updated : 22 July, 2025
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Sandeep Bhandari holds a Bachelor of Engineering in Computers from Thapar University (2006). He has 20 years of experience in the technology field. He has a keen interest in various technical fields, including database systems, computer networks, and programming. You can read more about him on his bio page.