Kilocalories (kcal) to Kilojoules (kJ) Conversion
Kilocalories
The kilocalorie (kcal), commonly called a "Calorie" (capital C) in nutritional contexts, is a unit of energy equal to exactly 4,184 joules. It represents the energy needed to raise 1 kg of water by 1 °C. In nutrition, all food energy values are expressed in kcal per gram: carbohydrates and protein provide 4 kcal/g; fat provides 9 kcal/g; alcohol provides 7 kcal/g. An average adult requires approximately 2,000–2,500 kcal per day to maintain body weight.
Kilojoules
The kilojoule (kJ) is a unit of energy equal to exactly 1,000 joules. It is the standard unit for expressing food energy in most countries outside the United States, where food labels display energy in both kilojoules and kilocalories (kcal). One kilocalorie equals exactly 4.184 kilojoules. In thermodynamics and chemistry, reaction enthalpies and bond energies are commonly tabulated in kilojoules per mole (kJ/mol).
| Kilocalories (kcal) | Kilojoules (kJ) |
|---|---|
| 0.1 kcal | 0.4184 kJ |
| 1 kcal | 4.184 kJ |
| 2 kcal | 8.368 kJ |
| 3 kcal | 12.552 kJ |
| 5 kcal | 20.92 kJ |
| 10 kcal | 41.84 kJ |
| 20 kcal | 83.68 kJ |
| 30 kcal | 125.52 kJ |
| 50 kcal | 209.20 kJ |
| 100 kcal | 418.40 kJ |
| 1000 kcal | 4,184.00 kJ |
Frequently Asked Questions (FAQ)
How many kilojoules are in 1 kilocalories?
1 kilocalories (kcal) is exactly 4.184 kilojoules (kJ).
How do I convert kilocalories to kilojoules?
Multiply the value in kilocalories by 4.184 to get the result in kilojoules. Or use the converter above — type any number and see the result instantly.