How many calories are in a kilojoule?

One kilojoule equals about 0.239 food calories (kcal). Divide your kilojoule figure by 4.184 to get calories.

Why do food labels use kilojoules?

Many countries, including Australia, use kilojoules as the official unit of food energy, while others use kilocalories — this tool converts between them.

Is anything uploaded?

No — every conversion happens locally in your browser and nothing is sent to a server.

Are food calories the same as kilocalories?

Yes. The "calories" on a nutrition label are kilocalories (kcal), sometimes written Cal with a capital C. One food calorie equals 1000 small (scientific) calories, and this tool works in kcal.

How do I convert calories back to kilojoules?

Multiply the calorie figure by 4.184. For example, 250 kcal × 4.184 = 1046 kJ. Type into the calories field and the converter returns kilojoules instantly.

How many kilojoules are in a 2000-calorie diet?

A 2000 kcal daily intake equals 8368 kJ (2000 × 4.184), close to the 8400 kJ reference value used on many food labels.

Kilojoules to Calories Converter

Kilojoules to calories converter

This tool converts food energy between kilojoules (kJ) and calories (kcal) in both directions. Many countries — including Australia and across the EU — print energy in kilojoules, while others, and most fitness apps, use kilocalories. The converter lets you read either label in the unit you think in.

How it works

It uses the exact thermochemical factor: kcal = kJ ÷ 4.184 (because one kilocalorie is defined as 4.184 kilojoules). To convert calories back to kilojoules it multiplies by 4.184 instead. Both fields are linked, so editing either one updates the other instantly.

Example

A muesli bar lists 900 kJ. To find the calories:

900 ÷ 4.184 = 215 kcal

So the bar holds about 215 food calories. All maths runs in your browser — no data leaves your device.