kJ to Calories Converter
Australian labels count energy in kilojoules; most apps and recipes count calories. Type a number into either box and get the other, instantly.
To convert kilojoules to calories, divide by 4.184 (or by 4 for a rough estimate). 8,700 kJ is about 2,080 calories, the daily reference on Australian labels. To go the other way, multiply calories by 4.184: 2,000 calories is about 8,370 kJ.
How to convert kJ to calories
One calorie, in the food sense, is 4.184 kilojoules. So:
- kJ to calories: divide by 4.184. 1,000 kJ is about 239 calories.
- Calories to kJ: multiply by 4.184. 500 calories is about 2,090 kJ.
- In your head: divide kJ by 4. It comes out about 5% high, which is close enough for a menu board.
The calories
on labels and in apps are kilocalories (kcal), sometimes written with a capital C as Cal
. They're the same thing; nobody counts the small calorie in food.
Common conversions
| Kilojoules | Calories | |
|---|---|---|
| 100 kJ | 24 Cal | |
| 500 kJ | 120 Cal | |
| 600 kJ | 143 Cal | one discretionary serve |
| 1,000 kJ | 239 Cal | |
| 2,000 kJ | 478 Cal | |
| 3,000 kJ | 717 Cal | |
| 4,000 kJ | 956 Cal | |
| 5,000 kJ | 1,195 Cal | |
| 6,000 kJ | 1,434 Cal | |
| 7,000 kJ | 1,673 Cal | |
| 8,000 kJ | 1,912 Cal | |
| 8,700 kJ | 2,079 Cal | Australian daily reference |
| 10,000 kJ | 2,390 Cal |
| Calories | Kilojoules |
|---|---|
| 100 Cal | 418 kJ |
| 500 Cal | 2,092 kJ |
| 1,200 Cal | 5,021 kJ |
| 1,500 Cal | 6,276 kJ |
| 1,800 Cal | 7,531 kJ |
| 2,000 Cal | 8,368 kJ |
| 2,500 Cal | 10,460 kJ |
The 600 kJ row is the Australian Dietary Guidelines' unit for one serve of a treat food or drink: roughly 200 ml of wine, two tablespoons of cream or half a small chocolate bar.
Why Australian labels use kilojoules
Under the Food Standards Code, the nutrition panel on packaged food in Australia and New Zealand has to show energy in kilojoules. Calories are optional, so many labels don't show them at all. That's why so many people end up converting at the supermarket. (More on tracking in kilojoules.)
What 8,700 kJ actually means
8,700 kJ, about 2,080 calories, is the average adult reference behind the % daily intake
figures on labels and the line on chain-restaurant menu boards. It's a yardstick, not a target. A smaller, less active person might need far less; a tall, active one far more. For a personal number, use the calorie deficit calculator.
Converting is the easy part. Keeping a running total across the day is what actually moves the needle, and it's the part most people give up on. Rekkon counts in kilojoules or calories, whichever you set: say what you ate and it does the adding up.
This converter uses the standard factor of 4.184 kJ per kilocalorie. Labels round their figures, so a converted label value can differ slightly from the calorie figure printed beside it. General information, not medical or dietary advice. If you have a history of disordered eating, please seek professional guidance before setting nutrition targets.
Stop converting. Just say what you ate.
Rekkon logs meals by voice and keeps the running total in kilojoules or calories, whichever you prefer. Seven days free.
Try Rekkon freeCommon questions
How many calories is 8,700 kJ?
8,700 kJ is about 2,080 calories (2,079 kcal). It's the average adult daily energy reference used on Australian food labels and menu boards, not a personal target.
How do I convert kJ to calories?
Divide the kilojoules by 4.184. For a quick estimate in your head, divide by 4, which comes out about 5% high: 8,700 kJ divided by 4 is 2,175, against the exact 2,079.
How do I convert calories to kJ?
Multiply the calories by 4.184. For example, 2,000 calories is about 8,370 kJ, and 500 calories is about 2,090 kJ.
Is a calorie on a food label the same as a kilocalorie?
Yes. The calories on food labels and in apps are kilocalories (kcal), sometimes written Cal. One kilocalorie is 4.184 kJ.
How many kilojoules should I eat a day?
8,700 kJ is an average reference, not a recommendation for you. Your needs depend on your size, age, sex, activity and goal. The calorie deficit calculator gives a personal estimate.