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Convert kilojoules to calories
Instant, accurate kJ → cal conversion with a live converter, table and formula.
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1 kilojoule = 239.006 calories
1 calorie = 0.004184 kilojoules
kilojoules to calories table
| kilojoules (kJ) | calories (cal) |
|---|---|
| 0.5 | 119.503 |
| 1 | 239.006 |
| 2 | 478.011 |
| 5 | 1195.03 |
| 10 | 2390.06 |
| 20 | 4780.11 |
| 50 | 11950.29 |
| 100 | 23900.57 |
| 500 | 119502.87 |
| 1000 | 239005.74 |
Formula
calories = kilojoules × 239.006.
Example
10 kilojoules = 2390.06 calories.
What is a kilojoule?
A kilojoule (kJ) is 1,000 joules; food energy is often labeled in kJ.
What is a calorie?
A calorie (cal) is the energy to heat 1 g of water by 1°C (4.184 J).
Real-world reference points
A food Calorie is a kilocalorie: an apple is ~52 kcal, a daily diet ~2,000 kcal (~8.4 MJ).
| Reference | kilojoules | calories |
|---|---|---|
| AA battery | 15.39 kJ | 3,678 cal |
| Smartphone battery (13 Wh) | 46.8 kJ | 11,185 cal |
| Apple (52 kcal) | 218 kJ | 52,000 cal |
| Daily diet (2,000 kcal) | 8,368 kJ | 2,000,000 cal |
| 1 kWh (unit of electricity) | 3,600 kJ | 860,000 cal |
Mistakes to avoid with energy conversions
- Food 'Calories' are kilocalories — mixing cal and kcal creates 1000× errors.
- Confusing kWh (energy) with kW (power) on bills and appliance labels.
- Comparing battery mAh across different voltages — energy needs Wh, not mAh alone.
Frequently asked questions
How many calories in a kilojoules?+
1 kilojoule = 239.006 calories.
How do I convert kilojoules to calories?+
Enter the value in the kilojoules box above and the calories value appears instantly. You can also type in the calories box to convert the other way.
Is this kJ to cal converter free?+
Yes — it is 100% free, needs no sign-up, and runs entirely in your browser.