Kilocalorie to Joule Converter

Convert kilocalories to joules (kcal to J) instantly with this free online energy converter. Enter any value in the Kilocalorie field and get the equivalent in Joule immediately. This converter handles any quantity — from tiny fractions to large numbers — with full precision. No signup, no ads in the widget, and the conversion runs entirely in your browser for instant results.

The conversion factor is exact: 1 kcal = 4184 J. To convert kilocalories to joules, multiply your Kilocalorie value by 4184. For example, 10 kcal = 41840 J. You can also reverse the calculation: 1 J = 0.0002390057361 kcal.

Quick conversion table

Kilocalorie (kcal) Joule (J)
1 kcal 4184 J
5 kcal 20920 J
10 kcal 41840 J
25 kcal 104600 J
50 kcal 209200 J
100 kcal 418400 J

Use the swap button to reverse the direction, or choose a different unit from the dropdown menus to convert within the energy category.

Result —
Formula —

Formula

Kilocalorie to Joule conversion:
1 kcal = 4184 J
joules = kilocalories × 4184
1 J = 0.0002390057361 kcal
kilocalories = joules × 0.0002390057361

Example

Example: Convert 10 kcal to J: 10 kcal × 4184 = 41840 J So, 10 kcal is about 41840 J. To convert back, multiply by 0.0002390057361: 41840 J × 0.0002390057361 = 10 kcal.

How to Use

  1. Enter the value you want to convert in the Kilocalorie field
  2. The result in Joule appears instantly below
  3. Use the dropdown menus to change units if needed
  4. Click 'Swap Units' to reverse the conversion direction
  5. Copy the result or adjust the input for a new conversion

Frequently Asked Questions

How do I convert kilocalories to joules?

Enter the value in Kilocalorie (kcal) in the 'From' field. The equivalent in Joule (J) appears instantly in the 'To' field. The converter uses precise conversion factors and updates in real time as you type.

What is the formula to convert kcal to J?

1 kcal = 4184 J, so joules = kilocalories × 4184. To convert back, 1 J = 0.0002390057361 kcal. The full formula and a worked example are shown on this page.

How many joules are in one Kilocalorie?

1 kcal = 4184 J.

Is this Kilocalorie to Joule converter free?

Yes, completely free with no signup, no limits, and no ads in the converter widget. You can convert as many values as you need. The tool runs entirely in your browser, so your data never leaves your device.

Can I convert joules back to kilocalories?

Yes. Click the 'Swap Units' button to reverse the direction. You can also use the dropdown menus to select any other energy unit for either field.

How accurate is the kcal to J conversion?

The converter uses high-precision conversion factors (up to 8 decimal places). Results are displayed with up to 6 decimal places, with trailing zeros removed for readability. For scientific or engineering work, always verify with official standards.