Convert kilojoule to kilocalorie (food cal).

Convert kilojoule (kJ) to kilocalorie (food cal) (kcal). This is a fixed-ratio conversion — multiply the input by the factor below.

Formula

kcal = kJ × 0.239006

Reference values

Things to watch for

• The 'calorie' in nutrition labels is actually a kilocalorie (kcal, sometimes Cal with capital C). A '200 calorie' candy bar is 200 kcal = 836 kJ.
• 1 kWh = 3.6 MJ (exactly). Used for billing electricity.
• Electron-volts (eV) are convenient at atomic/molecular scales; joules at human scales; kWh at building scales.

What is a kilojoule?

One kilojoule equals exactly 1,000 joules. Food energy labels in Europe and Australia (an apple is about 200 kJ), thermal calculations.

What is a kilocalorie (food calorie)?

One kilocalorie equals 1,000 small calories or about 4,184 joules. Food labels use "Calorie" (capitalized) to mean kcal. Food energy in the US — when a label says "240 Calories", it means 240 kcal.

Real-world examples of kJ

If the unit feels abstract, comparing it to known objects often helps. 1 kJ is the energy to lift a 100 kg adult one meter; 100 kJ is a chocolate-bar food label; and 2000 kJ is a typical meal's energy.

How to convert kilojoule to kilocalorie (food calorie)

To convert a value from kilojoule (kJ) to kilocalorie (food calorie) (kcal), apply the conversion factor shown in the formula above. The calculation is the same whether you do it by hand, in a spreadsheet, or with the live converter on this page.

Steps:

1. Take your input value in kJ.
2. Apply the formula kcal = kJ × 0.239006.
3. The result is your value in kcal.

For repeated calculations, save the formula in a spreadsheet or use the live converter at the top of this page — it handles the math automatically and displays the result as you type.

Frequently asked questions

How do I convert kJ to kcal?

Apply the formula kJ → kcal shown above, or just type your value into the converter at the top of this page. The result updates instantly.

Which is bigger, kJ or kcal?

This depends on the conversion ratio in the formula. If the factor multiplied by your value gives a larger number, then kcal is the smaller unit (so it takes more of them to express the same quantity). If the result is smaller, then kcal is the larger unit.

When would I use kJ versus kcal?

Both units measure energy, so the choice depends on context. Kilojoule is typically used for food labeling, batteries, fuel, and electric utility billing; kilocalorie (food calorie) similarly. Most professional fields standardize on one or the other based on regional conventions or technical tradition.

How precise is this kJ to kcal conversion?

The conversion factor shown is the internationally defined exact value (or the best-published approximation if the relationship is irrational, like degrees-to-radians). The live converter on this page uses double-precision floating-point math, accurate to about 15 significant digits — far beyond any practical engineering need.

Is the conversion ratio exact, or an approximation?

Most unit conversions between SI metric units, and between SI and US customary units, have been formally defined as exact values since the 1959 international yard-pound agreement and subsequent SI redefinitions. Exceptions are unit pairs that involve irrational numbers (radians, e.g.) or empirical conversions (like food calories, which depend on temperature). When in doubt, consult the formula at the top of this page.

Related conversions

See also