Food Energy Converter
Convert food energy between kilocalories (kcal), kilojoules (kJ), Calories (Cal), and watt-hours (Wh) instantly.
Type in any field — the others update instantly.
Food energy is the amount of energy stored in food that your body can use for fuel. Different countries and scientific fields use different units to express it.
Kilocalories (kcal) are the standard unit used on nutrition labels worldwide. When people say “calories” in everyday conversation, they almost always mean kilocalories. A chocolate bar with “250 calories” actually contains 250 kcal.
Calories (Cal) — with a capital C — are the same as kilocalories. This can be confusing because a lowercase “cal” (thermochemical calorie) is 1/1000 of a kcal. Nutrition labels always use the large Calorie (Cal = kcal).
Kilojoules (kJ) are the metric/SI unit for energy. Australia, New Zealand, and many European countries list kilojoules on food packaging alongside or instead of kcal.
Watt-hours (Wh) are an electrical energy unit sometimes used in scientific comparisons. One Wh equals 3.6 kJ.
Conversion factors (all based on 1 kcal = 4.184 kJ):
| From | To | Multiply by |
|---|---|---|
| 1 kcal | kJ | 4.184 |
| 1 kcal | Cal | 1 (they are equal) |
| 1 kcal | Wh | 1.1622 |
| 1 kJ | kcal | 0.2390 |
| 1 kJ | Wh | 0.2778 |
Typical food energy examples:
- 1 large apple: ~95 kcal / 397 kJ
- 1 slice of bread: ~80 kcal / 335 kJ
- 1 tablespoon of olive oil: ~120 kcal / 502 kJ
- 1 large egg: ~78 kcal / 326 kJ
Daily energy requirements vary by person, but a general adult reference value is 2,000 kcal (8,368 kJ) per day.