Kilocalories (kcal) to Calories (cal) 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.
Calories
The calorie (cal) is a unit of energy equal to exactly 4.184 joules, defined as the energy required to raise the temperature of one gram of water by one degree Celsius at 15 °C. This is the thermochemical calorie — distinct from the food calorie (written as Cal or kcal), which is 1,000 times larger. The calorie originated in 19th-century thermodynamics before the joule was established as the SI standard, and persists in chemistry, biology, and food science.
| Kilocalories (kcal) | Calories (cal) |
|---|---|
| 0.1 kcal | 100 cal |
| 1 kcal | 1000 cal |
| 2 kcal | 2000 cal |
| 3 kcal | 3000 cal |
| 5 kcal | 5000 cal |
| 10 kcal | 10000 cal |
| 20 kcal | 20000 cal |
| 30 kcal | 30000 cal |
| 50 kcal | 50000 cal |
| 100 kcal | 100000 cal |
| 1000 kcal | 1000000 cal |