kJ to Calories Converter
Convert between kilojoules (kJ) and food calories (kcal) quickly and accurately.
Quick Convert
Kilojoules (kJ)
1,000.0
kJ
Calories (kcal)
239.0
kcal
Conversion Formula
kJ to calories: Calories (kcal) = kJ ÷ 4.184
Calories to kJ: kJ = Calories (kcal) × 4.184
Note: These are food calories (kilocalories), not small calories. 1 food calorie = 1,000 small calories.
kJ to Calories Chart
| kJ | Calories (kcal) |
|---|---|
| 1 | 0.239 |
| 5 | 1.195 |
| 10 | 2.39 |
| 50 | 11.95 |
| 100 | 23.9 |
| 500 | 119.5 |
| 1000 | 239 |
| 2000 | 478 |
How to Use
- 1
Select conversion direction: kJ → Calories or Calories → kJ
- 2
Enter the energy value you want to convert
- 3
View the converted result instantly
- 4
Use the quick presets for common food items (kJ → Cal mode)
- 5
Reference the conversion chart for common values
Examples
Good Examples
Food label conversion
400 kJ ÷ 4.184 = 95.6 kcal (a glass of orange juice)Reverse conversion
500 kcal × 4.184 = 2,092 kJBad Examples
Confusing small calories with food calories
1 food calorie (kcal) = 1,000 small calories (cal)Using 4 instead of 4.184
Rounding the conversion factor too much reduces accuracyCommon Mistakes
- Confusing calories with kilocalories — food labels use kilocalories (kcal), also called "food calories"
- Using 4 instead of 4.184 as the conversion factor — this introduces a ~4.4% error
- Not knowing the direction — kJ ÷ 4.184 gives kcal, kcal × 4.184 gives kJ
- Confusing dietary energy with other energy units — this converter handles food energy only
Frequently Asked Questions
What is the difference between kJ and kcal?
kJ (kilojoules) and kcal (kilocalories) are both units of energy. 1 kcal = 4.184 kJ. Food calories on nutrition labels are actually kilocalories (kcal). Some countries (Australia, New Zealand) display kJ on food labels while the US and Europe typically use kcal.
How many kJ in a food calorie?
There are 4.184 kJ in 1 food calorie (kcal). To convert kJ to calories, divide by 4.184. To convert calories to kJ, multiply by 4.184.
How many calories are in 500 kJ?
500 kJ is approximately 119.5 calories (kcal). Calculate this by dividing 500 by 4.184.
Are food calories the same as scientific calories?
No — a food calorie (kcal) is 1,000 times larger than a scientific calorie (cal). When people say "calories" in the context of food, they mean kilocalories. This converter uses food calories.