Calories to Kilojoules Converter
Convert Calories to Kilojoules with the exact conversion factor, a worked example and a quick-reference table. Runs entirely in your browser.
This converter turns Calories into Kilojoules instantly using the standard definition of both units. It includes the formula, a worked example, and a quick table for common amounts, and it works for any value you type — including decimals and negatives where they make sense.
Quick reference — Calories to Kilojoules
How to use this calculator
- Enter the value in Calories in the input box.
- Read the result in Kilojoules — it updates as you type.
- Use the Swap button to convert in the opposite direction.
- Check the quick-reference table for common Calories amounts.
The formula
Kilojoules = Calories × 0.004184
Worked example
500 cal = 2.092 kJ — in full, 500 Calories converts to 2.092 Kilojoules. Food energy, electricity bills and heating are the everyday jobs for this conversion.
Frequently Asked Questions
How do I convert Calories to Kilojoules?
Multiply the value in Calories by 0.004184. For example, 500 Calories × 0.004184 = 2.092 Kilojoules. To go the other way, divide by 0.004184 instead — or press Swap in the converter above.
How many Kilojoules are in one Calorie?
One Calorie equals 0.004184 Kilojoules. Scaling up, 10 Calories = 0.04184 Kilojoules and 100 Calories = 0.4184 Kilojoules. The converter uses the full-precision factor, so typed values are more precise than the rounded figure quoted here.
Which is bigger, a Calorie or a Kilojoule?
A Kilojoule is bigger. One Kilojoule equals 239.006 Calories, while one Calorie is only 0.004184 Kilojoules. So a measurement that looks smaller in Kilojoules is reflecting the scale difference, not an error.
What is 500 Calories in Kilojoules?
500 Calories is 2.092 Kilojoules. The math is 500 × 0.004184 = 2.092. Try any other amount in the converter above and the result updates as you type.