kJ to Calories Converter – Convert kJ to Calories (Australia)
Use this free kJ to calories converter to convert kJ to calories (kcal) and back in one step. It is built for Australian food labels, so you can compare snacks, drinks and protein bars and work out the energy in a single serve. Type in either box and the other updates instantly.
kJ to calories converter
Quick values:
Enter a value above to convert it. Formula: 1 kcal = 4.184 kJ.
Energy per serving calculator
Enter the energy per 100 g from the label and your serving size.
Your serving energy will appear here.
Estimate energy from protein, carbs and fat
Enter grams per serve to see the energy using Australian labelling factors.
Your estimate will appear here.
How to convert kJ to calories (formula)
The kJ to calories formula is simple: divide kilojoules by 4.184 to get calories (kilocalories, kcal). To convert calories to kJ, multiply by 4.184. On food, "calories" always means kilocalories, so 1 Calorie = 1 kcal = 4.184 kJ.
Worked example: a muesli bar lists 780 kJ per serve. 780 ÷ 4.184 = 186 kcal. A 150 kcal snack is 150 × 4.184 = 628 kJ.
Common kJ to calories conversions
| Kilojoules | Calories (kcal) | Kilojoules | Calories (kcal) |
|---|---|---|---|
| 100 kJ | 24 kcal | 1,500 kJ | 359 kcal |
| 200 kJ | 48 kcal | 1,600 kJ | 382 kcal |
| 300 kJ | 72 kcal | 2,000 kJ | 478 kcal |
| 500 kJ | 120 kcal | 2,500 kJ | 598 kcal |
| 600 kJ | 143 kcal | 3,000 kJ | 717 kcal |
| 800 kJ | 191 kcal | 4,000 kJ | 956 kcal |
| 1,000 kJ | 239 kcal | 5,000 kJ | 1,195 kcal |
| 1,200 kJ | 287 kcal | 8,700 kJ | 2,079 kcal |
So 1000 kJ to calories is about 239 kcal, 2000 kJ is about 478 kcal, and 500 kJ is about 120 kcal.
How to read energy on an Australian nutrition panel
Packaged foods sold in Australia must show energy in kilojoules on the nutrition information panel (NIP). The panel has two columns. Per serving shows the amount the maker defines as one serve, which differs between brands. Per 100 g or 100 mL is the best column for comparing products fairly.
How food energy is calculated
Food Standards Australia New Zealand (FSANZ) sets energy factors for labelling: protein 17 kJ/g, available carbohydrate 16 kJ/g, fat 37 kJ/g, dietary fibre 8 kJ/g and alcohol 29 kJ/g.
What is 8700 kJ in calories?
Australian labels use 8,700 kJ a day as the average adult reference for the percentage daily intake. 8700 kJ to calories is about 2,079 kcal. Your own needs depend on age, size, sex and activity, so treat it as a guide, not a target.
Kilojoules in protein bars, snacks and drinks
Protein bars, nuts, dried fruit and drinks vary widely in energy. Converting the label to calories makes it easier to compare them with overseas products or an app. Browse protein bars, Fibre Boost bars, healthy snacks and drinks.
Frequently asked questions
How many calories are in 1 kJ?
1 kilojoule equals about 0.239 calories (kcal). So 1,000 kJ is roughly 239 kcal.
How do I convert calories to kJ?
Multiply calories (kcal) by 4.184. For example, 250 kcal × 4.184 = 1,046 kJ.
Is a calorie the same as a kcal?
On food labels, yes. "Calories" means kilocalories (kcal). A small "calorie" (cal) is 1,000 times smaller and is used in science, not nutrition.
Why does my calculation differ from the label?
Manufacturers may round values and use official energy factors for each nutrient, so the label can differ by a few percent from a simple conversion.
How many kJ should I eat a day?
Labels use 8,700 kJ (about 2,080 kcal) as an average adult reference. Your own needs may be higher or lower. For personal advice speak to an accredited practising dietitian or your doctor.
Related free tools
Protein calculatorMacro calculatorAll free nutrition tools
General information only, not medical or dietary advice. Results are estimates.