Calories to Joules Converter
Convert Calories to Joules with the exact conversion factor, a worked example and a quick-reference table. Runs entirely in your browser.
This converter turns Calories into Joules 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 Joules
How to use this calculator
- Enter the value in Calories in the input box.
- Read the result in Joules — 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
Joules = Calories × 4.184
Worked example
100 cal = 418.4 J — in full, 100 Calories converts to 418.4 Joules. Food energy, electricity bills and heating are the everyday jobs for this conversion.
Frequently Asked Questions
How do I convert Calories to Joules?
Multiply the value in Calories by 4.184. For example, 100 Calories × 4.184 = 418.4 Joules. To go the other way, divide by 4.184 instead — or press Swap in the converter above.
How many Joules are in one Calorie?
One Calorie equals 4.184 Joules. Scaling up, 10 Calories = 41.84 Joules and 100 Calories = 418.4 Joules. 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 Joule?
A Calorie is bigger. One Calorie equals 4.184 Joules, while one Joule is only 0.239006 Calories. So a measurement that looks larger in Joules is reflecting the scale difference, not an error.
What is 100 Calories in Joules?
100 Calories is 418.4 Joules. The math is 100 × 4.184 = 418.4. Try any other amount in the converter above and the result updates as you type.