Calories to Kilojoules Converter
Convert kilocalories (kcal) to kilojoules (kJ) or kJ to kcal instantly. Enter a value in either field — useful for reading Australian, NZ, or European food labels.
kcal ↔ kJ
1 kcal = 4.184 kJ · 1 kJ = 0.2390 kcal
Food energy is labelled in kilocalories (kcal) in the US and most of Europe, but in kilojoules (kJ) in Australia, New Zealand, and on some EU labels that display both. The conversion is simple: 1 kcal = 4.184 kJ. This tool works instantly in both directions — paste any number from a food label and get the equivalent in the other unit.
Common Food Items — kcal and kJ Reference
| Food (typical serving) | Calories (kcal) | Kilojoules (kJ) |
|---|---|---|
| Large egg (50 g) | 72 kcal | 301 kJ |
| Banana (medium, 120g) | 105 kcal | 439 kJ |
| White rice, cooked (100 g) | 130 kcal | 544 kJ |
| Chicken breast (100 g, grilled) | 165 kcal | 690 kJ |
| Whole milk (250 ml) | 150 kcal | 628 kJ |
| Whey protein scoop (30 g) | 120 kcal | 502 kJ |
| Slice of bread (30 g) | 79 kcal | 331 kJ |
| Peanut butter (2 tbsp, 32g) | 190 kcal | 795 kJ |
| Big Mac (McDonald's) | 550 kcal | 2301 kJ |
| Daily total (sedentary adult) | 2000 kcal | 8368 kJ |
Calories vs Kilojoules — What You Need to Know
The kilocalorie (kcal) is the unit of food energy most familiar to Americans and Europeans. The kilojoule (kJ) is the official SI metric unit used across Australia, New Zealand, and some other countries. The relationship is fixed: 1 kcal = 4.184 kJ exactly. If your daily calorie target is 2,500 kcal, that equals 10,460 kJ. When reading Australian or New Zealand food labels, divide the kJ figure by 4.184 to get the familiar calorie count. The macronutrient energy densities are: protein = 4 kcal/g (16.7 kJ/g), carbohydrates = 4 kcal/g, fat = 9 kcal/g (37.7 kJ/g), alcohol = 7 kcal/g (29.3 kJ/g).