Definition: A kilocalorie, often just called 'calorie' in dietary contexts, is the amount of energy required to raise the temperature of one kilogram of water by one degree Celsius.
History/origin: The calorie was originally defined in the 19th century as a unit of heat energy.
Current use: Kilocalories are commonly used to express the energy content of foods in many countries, especially in nutrition and dietetics.
Definition: A kilojoule is a unit of energy in the International System of Units (SI), equivalent to 1,000 joules.
History/origin: The joule is named after James Prescott Joule and has been widely adopted as the standard unit of energy.
Current use: Kilojoules are used worldwide in science, engineering, and nutrition to measure energy.
| Kilocalories (kcal) | Kilojoules (kJ) |
|---|---|
| 1.000 | 4.184 |
| 2.000 | 8.368 |
| 5.000 | 20.920 |
| 10.000 | 41.840 |
| 15.000 | 62.760 |
| 20.000 | 83.680 |
| 0.500 | 2.092 |
| 0.100 | 0.418 |
| 7.500 | 31.380 |
| 12.300 | 51.463 |
1 kilocalorie = 4.184 kilojoules
1 kilojoule = 0.239006 kilocalories
Example: convert 50 kilocalories to kilojoules:
50 × 4.184 = 209.2 kilojoules