Joule to Calorie Converter
Enter the value that you want to convert joule (J) to calorie (cal) or calorie to joule.Also written as J to CAL conversion.
1 joule = 0.2390057 calorie
Formula: calorie = joule value × 0.2390057
J to CAL — joule to calorie
10 joule = 2.39006 calorie
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Converting Joule to Calorie
The Joule in Engineering
Joule (J) is a unit of energy measurement. 1 joule is equal to 0.2390057 calorie.
About the Calorie
Calorie (cal) is a unit of energy measurement. 1 calorie is equal to 4.1840000 joule.
Energy Units in Different Fields
Energy measurement units reflect their historical origins across different industries. Electrical engineers use kilowatt-hours, nutritionists use calories, physicists use joules, heating engineers use BTUs, and the petroleum industry uses barrels of oil equivalent. Converting between these units is essential for energy auditing, comparing fuel sources, sizing HVAC systems, and understanding electricity bills relative to gas consumption.
joule to calorie metric conversion table
| 0.01 J | = | 0.00239 cal |
| 0.1 J | = | 0.02390 cal |
| 1 J | = | 0.23901 cal |
| 2 J | = | 0.47801 cal |
| 3 J | = | 0.71702 cal |
| 4 J | = | 0.95602 cal |
| 5 J | = | 1.19503 cal |
| 6 J | = | 1.43403 cal |
| 7 J | = | 1.67304 cal |
| 8 J | = | 1.91205 cal |
| 9 J | = | 2.15105 cal |
| 10 J | = | 2.39006 cal |
| 11 J | = | 2.62906 cal |
| 12 J | = | 2.86807 cal |
| 13 J | = | 3.10707 cal |
| 14 J | = | 3.34608 cal |
| 15 J | = | 3.58509 cal |
| 16 J | = | 3.82409 cal |
| 17 J | = | 4.06310 cal |
| 18 J | = | 4.30210 cal |
| 19 J | = | 4.54111 cal |
| 20 J | = | 4.78011 cal |
| 30 J | = | 7.17017 cal |
| 40 J | = | 9.56023 cal |
| 50 J | = | 11.95029 cal |
| 60 J | = | 14.34034 cal |
| 70 J | = | 16.73040 cal |
| 80 J | = | 19.12046 cal |
| 90 J | = | 21.51052 cal |
| 100 J | = | 23.90057 cal |
| 200 J | = | 47.80115 cal |
| 300 J | = | 71.70172 cal |
| 400 J | = | 95.60229 cal |
| 500 J | = | 119.50287 cal |
| 600 J | = | 143.40344 cal |
| 700 J | = | 167.30402 cal |
| 800 J | = | 191.20459 cal |
| 900 J | = | 215.10516 cal |
| 1000 J | = | 239.00574 cal |
How to Convert J to CAL (Joule to Calorie)?
We can convert joule to calorie by using an example.
Example:
Convert 20 Joule to Calorie?
We know 1 Joule = 0.2390057 calorie; 1 Calorie = 4.1840000 joule.
20 joule = ___cal
20 × 0.2390057 = 4.78011 cal (we know 1 joule = 0.2390057 calorie)
Answer:
20 joule = 4.78011 calorie
How to Convert Joules to Calories (Step-by-Step)
Converting joules to calories connects the SI energy unit to the thermal unit still used in nutrition and older scientific literature. The conversion factor is 1 cal = 4.184 J (thermochemical calorie).
- Identify the energy value in joules (J).
- Divide by 4.184 to get thermochemical calories (cal).
- For food Calories (kcal), divide joules by 4184 instead.
- Apply appropriate significant figures based on your measurement precision.
Common Joules to Calories Conversions
Converting physics energy measurements to calorie equivalents for nutrition and chemistry context.
| Joule | Calorie |
|---|---|
| 4.184 J | 1 cal |
| 100 J | 23.9 cal |
| 1000 J | 239.0 cal |
| 4184 J | 1000 cal (1 kcal) |
| 10,000 J | 2390 cal |
| 100,000 J | 23,900 cal (23.9 kcal) |
| 1,000,000 J | 239,006 cal (239 kcal) |
Solved Examples: Joules to Calories Conversion
Question 1: A student measures 836.8 J of heat released in a calorimetry experiment. How many calories is that?
Solution:
Start with 836.8 J.
Divide by 4.184: 836.8 ÷ 4.184 = 200.0 cal.
This would raise 200 g of water by 1°C.
Answer: 836.8 J = 200.0 cal
Question 2: Running for 30 minutes burns approximately 1,255,200 J. Convert to food Calories.
Solution:
Start with 1,255,200 J.
Divide by 4184 to get kcal: 1,255,200 ÷ 4184 = 300 kcal.
Or divide by 4.184 first: 1,255,200 ÷ 4.184 = 300,000 cal = 300 kcal.
Answer: 1,255,200 J = 300,000 cal = 300 kcal (food Calories)
Question 3: A physics textbook gives the energy of a snack bar as 920,000 J. How many food Calories?
Solution:
Start with 920,000 J.
Divide by 4184: 920,000 ÷ 4184 = 219.9 kcal.
The snack bar is about 220 Calories.
Answer: 920,000 J ≈ 220 food Calories (kcal)
Question 4: Specific heat problem: How many calories to heat 50 g of water by 10°C?
Solution:
Energy in joules: Q = mcΔT = 0.05 kg × 4184 J/(kg⋅°C) × 10°C = 2092 J.
Convert to cal: 2092 ÷ 4.184 = 500 cal.
Cross-check: 50 g × 10°C × 1 cal/(g⋅°C) = 500 cal ✓.
Answer: 2092 J = 500 cal
Practice: Joules to Calories Conversions
Try solving these on your own to test your understanding:
- Convert 2092 J to cal. (Answer: 500 cal)
- A reaction releases 15,000 J. Express in cal. (Answer: ≈ 3585 cal)
- Convert 8,368,000 J to food Calories. (Answer: ≈ 2000 kcal)
- How many calories in 500 J? (Answer: ≈ 119.5 cal)
- A workout burns 2,510,400 J. How many kcal? (Answer: ≈ 600 kcal)
Joules vs Calories: When to Use Which
Joules are the SI standard and preferred in physics, engineering, and modern chemistry. Calories persist in nutrition (due to food labeling tradition), older chemistry textbooks, and some biological sciences. The thermochemical calorie (4.184 J) is used in chemistry, while the International Table calorie (4.1868 J) is used in nutrition. The difference is less than 0.1%.
Exercise Energy Expenditure in Joules
The human body at rest uses about 80 J/s (80 watts). Walking increases this to ~300 J/s, jogging to ~600 J/s, and sprinting to ~1500 J/s. A 30-minute jog at 600 J/s expends 1,080,000 J = 258 kcal. Fitness trackers convert these joule rates to "Calories burned" for user-friendly display.
The Thermochemical vs International Table Calorie
Two slightly different calorie definitions exist: the thermochemical calorie (4.184 J exactly, used in chemistry) and the International Table calorie (4.1868 J exactly, used in food/nutrition). For most practical purposes the difference is negligible (0.07%). Use 4.184 for chemistry problems and 4.1868 for nutrition calculations.
Key Takeaways
- Divide joules by 4.184 to get thermochemical calories.
- Divide joules by 4184 to get food Calories (kcal) directly.
- Quick mental math: divide J by 4.2 for approximate cal.
- 1 food Calorie = 1 kcal = 4184 J = 4.184 kJ.
- Chemistry uses the thermochemical calorie (4.184 J); nutrition uses IT calorie (4.1868 J).
- The human body uses ~80 J/s at rest, ~600 J/s jogging.
Joule to Calorie Conversion Formula
calorie = joule × 0.2390057
1 joule = 0.2390057 calorie
1 calorie = 4.1840000 joule
Reverse: joule = calorie × 4.1840000
Frequently Asked Questions
How many calorie are in 1 joule?
There are 0.2390057 calorie in 1 joule. To convert joule to calorie, multiply the value by 0.2390057.
How do I convert joule to calorie?
Multiply your joule value by 0.2390057 to get the equivalent in calorie. For example, 5 joule = 5 × 0.2390057 = 1.19503 calorie.
How do I convert calorie to joule?
Multiply your calorie value by 4.1840000 to get the equivalent in joule. Alternatively, divide by 0.2390057.
What is 10 joule in calorie?
10 joule is equal to 2.39006 calorie.
What is 100 joule in calorie?
100 joule is equal to 23.90057 calorie.