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Kilojoules to Calories: kJ to kcal Converter and Chart
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Short answer: to turn kilojoules into calories, divide by 4.184 — 1,000 kJ is about 239 calories. To go the other way, multiply calories by 4.184: 500 calories is about 2,092 kJ. For a quick estimate in your head, divide kJ by 4 and take off a little.
Kilojoules (kJ) and calories (kcal) measure the same thing — the energy in food — on two different scales. Australia and New Zealand print kilojoules on every nutrition panel; the US, Canada and most apps talk in calories. Here's how to move between them without a calculator open in another tab.
The formula
One kilocalorie is defined as exactly 4.184 kilojoules. So:
- kJ → calories: calories = kJ ÷ 4.184
- calories → kJ: kJ = calories × 4.184
A note on words. The "calories" on a US label or in a fitness app are really kilocalories (kcal) — sometimes written with a capital C, "Calories". Nobody counts the tiny lowercase calorie in everyday life, so in this article, as on food labels, "calories" means kcal.
Shortcut: divide kJ by 4, then subtract about 5%. For 2,000 kJ that's 500 − 25 = 475; the exact answer is 478. Close enough for a menu board.
Quick conversion chart
| Kilojoules (kJ) | Calories (kcal) |
|---|---|
| 100 kJ | 24 kcal |
| 250 kJ | 60 kcal |
| 500 kJ | 120 kcal |
| 1,000 kJ | 239 kcal |
| 1,500 kJ | 359 kcal |
| 2,000 kJ | 478 kcal |
| 3,000 kJ | 717 kcal |
| 5,000 kJ | 1,195 kcal |
| 8,700 kJ | 2,079 kcal |
| 10,000 kJ | 2,390 kcal |
And the other direction, for anyone used to calories who is reading an Australian label:
| Calories (kcal) | Kilojoules (kJ) |
|---|---|
| 100 kcal | 418 kJ |
| 200 kcal | 837 kJ |
| 500 kcal | 2,092 kJ |
| 1,500 kcal | 6,276 kJ |
| 2,000 kcal | 8,368 kJ |
| 2,500 kcal | 10,460 kJ |
Why Australia and New Zealand use kilojoules
Both countries share one food law, the Australia New Zealand Food Standards Code. Its nutrition labelling rules (Standard 1.2.8) say the nutrition information panel must show average energy in kilojoules — calories may be added alongside, but they are optional. That's why many Australian packs show only kJ.
The same standard explains the "% daily intake" figure on the front or side of a pack. Percentages are based on an average adult diet of 8,700 kJ — about 2,080 calories. It's a reference point for comparing foods, not a personal target: a tall, active person may need far more, a small, sedentary person less.
How is the kJ number on a label worked out? Mostly by calculation, with energy factors set in the Code (Schedule 11): fat gives 37 kJ per gram, protein and available carbohydrate 17 kJ, alcohol 29 kJ and dietary fibre 8 kJ. These are the kilojoule versions of the familiar 9 / 4 / 4 calories per gram.
[!note] Same food, two numbers A label reading "Energy 1,670 kJ" and a US-style label reading "399 calories" describe the same amount of energy. Nothing about the food changes — only the unit.
Popular Aussie foods in kJ and calories
Numbers are from our food database. The Australian items come from Food Standards Australia New Zealand's food composition tables (AFCD and AUSNUT), so they match what you'd see on a typical product.
| Food | Serving | Kilojoules | Calories |
|---|---|---|---|
| Meat pie | 1 pie, 175 g | ~1,670 kJ | ~400 kcal |
| Sausage roll | 1 roll, 130 g | ~1,545 kJ | ~370 kcal |
| Chicken parmigiana | 250 g, no chips | ~2,290 kJ | ~550 kcal |
| Flat white | 240 ml | ~570 kJ | ~137 kcal |
| Anzac biscuit | 1 biscuit, 27 g | ~525 kJ | ~125 kcal |
| Lamington | 1 finger, 40 g | ~495 kJ | ~118 kcal |
| Pavlova | 1 serve, 120 g | ~1,095 kJ | ~262 kcal |
| Barramundi, grilled | 1 large fillet, 128 g | ~915 kJ | ~219 kcal |
| Banana | 1 medium, 120 g | ~480 kJ | ~115 kcal |
Two things stand out. A pie and a sausage roll each take up close to a fifth of the 8,700 kJ reference day. And a parma, before the chips and salad, is already over a quarter of it. That doesn't make them off-limits — it just helps to know where a meal sits.
kJ on a bike computer or fitness watch
Cyclists see kilojoules on power meters and ride summaries, and that number means something different: it's the mechanical work your legs put into the pedals, not the food energy you used. The body turns only about 20–25% of the food energy it burns into pedalling, and a kilocalorie is about four kilojoules — the two factors roughly cancel out. So the rule of thumb is: kJ of work on a ride ≈ calories burned. A ride showing 575 kJ used roughly 575 calories, not 137.
Food labels and calorie apps are the other case: there kJ and kcal measure the same food energy, so divide by 4.184.
How many kilojoules a day do you need?
8,700 kJ is the labelling reference, not a prescription. Your own number depends on your sex, age, size and how much you move. The usual approach:
- Estimate your basal metabolic rate — the energy you use at complete rest.
- Multiply it by an activity factor to get maintenance energy.
- Adjust: about 15% less for gentle weight loss, a little more for gain.
Our calculator does the arithmetic and shows the result in both calories and kilojoules. It works in kilograms and centimetres by default if your device is set to Australia, New Zealand or Canada.
[!tip] Don't chase the decimal Labels round, portions are eyeballed, and two pies from the same bakery are rarely identical. Being within a few hundred kJ of your target over a week matters far more than the exact figure on any single day.
Tracking in kilojoules
In Calories Not Count, you can switch the whole app between kcal and kJ in Profile → Energy units. If your phone is set to Australia or New Zealand, it starts in kilojoules. Your daily target, every food, the day's totals, the weekly charts and the doctor's report all follow the setting. You can type energy in kJ straight off an Australian label when you add a food by hand.
Behind the scenes, your diary is stored the same way either way, so switching back and forth never changes your history. The food database also speaks local English: search "capsicum", "courgette", "yoghurt" or "hot chips" and you'll find what you meant. If you'd rather not type at all, see how a photo calorie counter handles a plate in one shot, or browse healthy food swaps for lighter options at the same energy.
Frequently asked questions
How do I convert kJ to calories?
Divide the kilojoules by 4.184. For example, 1,500 kJ ÷ 4.184 = 359 calories. A quick mental version is to divide by 4 and subtract about 5%.
How many calories is 8,700 kJ?
About 2,079 calories (kcal). It's the average adult diet that Australian and New Zealand labels use for "% daily intake", not a personal target.
Does 1 kJ equal 1 calorie?
No — a calorie (kcal) is about four times bigger. One kcal equals 4.184 kJ, which is why kJ numbers on a label look roughly four times larger. The one place they come out about equal is the work figure on a bike computer, explained above.
How much is 2,000 calories in kJ?
2,000 calories × 4.184 = 8,368 kJ. That's a little under the 8,700 kJ (about 2,080 calories) that Australian and New Zealand labels use as the average adult day.
Why do Australian labels show kJ instead of calories?
The Australia New Zealand Food Standards Code requires energy in kilojoules on the nutrition information panel. Calories may be added, but they're optional.
Are "Cal" and "kcal" the same thing?
Yes. "Calories" on food labels and in apps — sometimes written "Cal" — are kilocalories. The small "calorie" (cal) is 1/1,000 of that and is not used for food.
Sources
- Food Standards Australia New Zealand. Australia New Zealand Food Standards Code – Standard 1.2.8 – Nutrition information requirements.
- Food Standards Australia New Zealand. Australia New Zealand Food Standards Code – Schedule 11 – Calculation of values for nutrition information panel.
- Food Standards Australia New Zealand. Australian Food Composition Database (AFCD).
- Food Standards Australia New Zealand. Nutrition information panels.