Convert Kilocalories to Kilojoules
One kilocalorie equals 4.184 kilojoules. Type any value to convert kilocalories to kilojoules instantly — with a full reference table below.
Convert Kilocalories to Kilojoules
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How to convert Kilocalories to Kilojoules
To convert kilocalories to kilojoules, multiply by 4.184. One kilocalorie equals 4.184 kJ, and one kilojoule equals 0.239006 kcal.
- Take the value in kilocalories — for example 7.5 kcal.
- Multiply by 4.184 (the number of kilojoules in one kilocalorie).
- 7.5 × 4.184 = 31.38 kJ.
Quick mental estimate: Multiply the number of kilocalories by 4.2 (within 0.4% of the exact answer).
Kilocalories to Kilojoules conversion table
| Kilocalories | Kilojoules |
|---|---|
| 1 kcal | 4.184 kJ |
| 2 kcal | 8.368 kJ |
| 5 kcal | 20.92 kJ |
| 10 kcal | 41.84 kJ |
| 20 kcal | 83.68 kJ |
| 50 kcal | 209.2 kJ |
| 100 kcal | 418.4 kJ |
| 200 kcal | 836.8 kJ |
| 500 kcal | 2,092 kJ |
| 1,000 kcal | 4,184 kJ |
| 2,000 kcal | 8,368 kJ |
| Kilojoules | Kilocalories |
|---|---|
| 1 kJ | 0.239006 kcal |
| 2 kJ | 0.478011 kcal |
| 5 kJ | 1.195029 kcal |
| 10 kJ | 2.390057 kcal |
| 20 kJ | 4.780115 kcal |
| 50 kJ | 11.95029 kcal |
| 100 kJ | 23.90057 kcal |
| 200 kJ | 47.80115 kcal |
| 500 kJ | 119.5029 kcal |
| 1,000 kJ | 239.0057 kcal |
| 2,000 kJ | 478.0115 kcal |
About converting Kilocalories to Kilojoules
Kilocalories (kcal) and Kilojoules (kJ) are both units of energy. The exact factor is 1 kcal = 4.184 kJ, so multiply by 4.184 to go from kilocalories to kilojoules (or divide to go back).
The conversion runs entirely in your browser. Need the reverse? Use the Kilojoules to Kilocalories converter, or the full unit converter for every unit at once.
Real-world energy in kilocalories and kilojoules
| Example | Kilocalories | Kilojoules |
|---|---|---|
| One food Calorie (kcal) | 1 kcal | 4.184 kJ |
| A 100 W bulb running for one hour | 86.04207 kcal | 360 kJ |
| A smartphone battery (≈19 Wh) | ≈ 16.5631 kcal | ≈ 69.3 kJ |
| A 2,000 kcal daily diet | 2,000 kcal | 8,368 kJ |
| One kilowatt-hour | 860.4207 kcal | 3,600 kJ |
“≈” marks typical values; the rest are defined or measured figures.
The units
1,000 calories, exactly 4,184 J — the 'Calorie' on food labels.
Used for: Nutrition and diets.
1,000 joules.
Used for: Food energy on labels in Australia and the EU.
The thermochemical calorie is exactly 4.184 J and a kilowatt-hour is exactly 3.6 MJ, so these factors are exact.