Calories to Kilojoules Converter
Convert calories to kilojoules or kJ back to kcal instantly with this free food energy converter that works right in your browser.
Convert energy
Result
4.184
1 Kilocalories / Calories (kcal) = 4.184 Kilojoules (kJ)
All units
- Kilocalories / Calories (kcal)
- 1
- Kilojoules (kJ)
- 4.184
- Calories (cal)
- 1,000
- Joules (J)
- 4,184
- Watt-hours (Wh)
- 1.162222
Before you rely on this: First-pass guide only. Verify safety-critical or regulated work against the relevant standards, your project requirements and a qualified professional.
How to use this calculator
- Enter the amount you want to convert.
- Choose the unit you have (From) and the unit you want (To).
- Read the result instantly — every other unit is listed too.
How it works
Converts food energy from calories to kilojoules by multiplying by 4.184 — the unit on Australian food labels.
Worked example
100 calories. = 418.4 kJ.
Frequently asked questions
Are food 'calories' the same as kilojoules?
No — but they're related: 1 food calorie (kcal) = 4.184 kJ. Australian and NZ labels use kJ, while US labels use calories.
How accurate are the conversions?
They use standard conversion factors at full device precision, so they're reliable for everyday and professional use.
Does it work offline and stay private?
Yes — the conversion runs entirely in your browser, with no sign-up and nothing sent to a server.
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Cite this tool
Zerdly. (2026). Calories to Kilojoules Converter. Retrieved from https://www.zerdly.com/tools/calories-kilojoules-converter/
Tip: Enter any known values to calculate the remaining results.
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