Convert Energy from calories to Kilocalories (cal to kcal)

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Single conversion

calorie to Kilocalorie Conversion Formula

To convert from calorie (cal) to Kilocalorie (kcal), use the following formula:

Kilocalorie (kcal)

= 11000× calorie (cal)

= 0.001× calorie (cal)


Example

Let's convert 5 calorie (cal) to Kilocalorie (kcal).

Using the formula:

5 × 0.001 = 0.005

Therefore, 5 calorie (cal) is equal to 0.005 Kilocalorie (kcal).

How many calories are in one kilocalorie? One Kilocalorie (kcal) contains 1000 calories (cal) — the inverse of the factor above. Multiplying by 0.001 takes you from calories to kilocalories; multiplying by 1000 brings you back.

Put in words: one calorie equals 0.001 kilocalories, so the calorie is the smaller unit of this pair. Converting between them never changes the amount of energy being measured — only the size of the unit you count it in.

What is a calorie (cal)?

At its core, a calorie (cal) is a fundamental unit of energy.

While we often talk about "calories" in our food, it's essential to understand precisely what they represent.


Are Food Calories Actually Kilocalories?

Have you ever noticed the term "calorie" on a nutrition label? What you're actually looking at is a kilocalorie (kcal).

One kilocalorie (or "food calorie") is equal to 1,000 of the smaller, scientific calories.

The scientific definition of a single, "small" calorie (cal) is the amount of energy needed to raise the temperature of one gram of water by one degree Celsius.

Knowing this difference is key to accurate calorie counting and managing your energy intake for your health and fitness goals.


How Calories in Food Are Calculated

Scientists use two primary methods to determine the number of calories in food:

  • The Bomb Calorimeter: This is the most precise method. It involves an instrument that measures the total heat released when a food sample is burned completely.

  • The Atwater System: This is a more common and practical method. It calculates the total energy by using average values: 4 calories per gram for carbohydrates and proteins, and 9 calories per gram for fats.


Is It Just Food? Calories in Other Things

Calories aren't just for food—they are a universal measure of energy. Anything that stores and releases energy has a calorie value.

For example, you might be surprised to learn that a single gallon of gasoline contains over 31 million calories!

This shows that a calorie is simply a standard unit for potential energy, whether it's fueling your body or powering a car.

What Is a Kilocalorie (kcal)?

A kilocalorie (kcal) is a unit used to measure energy.

Just as a kilometer is 1,000 meters, one kilocalorie is equal to 1,000 small calories (cal).

It's the most common unit for discussing the energy content of food.


Kilocalorie vs. Calorie: What's the Difference?

Have you ever noticed the word "Calories" on a food label? What you're actually seeing is a kilocalorie (kcal).

Here's the simple breakdown:

  • 1 Calorie (with a capital C), also known as a food Calorie, is equal to 1 kilocalorie (kcal).
  • 1 kilocalorie (kcal) is equal to 1,000 calories (with a lowercase c).

Essentially, in the world of nutrition, the terms Calorie and kilocalorie are used interchangeably.

The "small calorie" (cal) is a much smaller unit and is primarily used in science labs.


How Are Kilocalories Measured?

Scientifically, a kilocalorie is the amount of energy needed to heat one kilogram of water by one degree Celsius.

This precise measurement allows scientists to determine how much energy your body can get from the macronutrients in your food, such as:

  • Carbohydrates
  • Proteins
  • Fats

When a food label says a serving has 100 Calories, it means that's the amount of energy your body can use from it.


More Than Just Food: Other Uses for the Kilocalorie

The kilocalorie isn't just for food!

As a fundamental unit of energy, it's also used in fields like physics and chemistry to measure energy in chemical reactions and heat transfer.

calorie to Kilocalorie Conversion Table

Here are some quick reference conversions from calorie (cal) to Kilocalorie (kcal):

caloriesKilocalories
0.000001 cal10-9 kcal
0.001 cal10-6 kcal
0.1 cal10-4 kcal
1 cal0.001 kcal
2 cal0.002 kcal
3 cal0.003 kcal
4 cal0.004 kcal
5 cal0.005 kcal
6 cal0.006 kcal
7 cal0.007 kcal
8 cal0.008 kcal
9 cal0.009 kcal
10 cal0.01 kcal
20 cal0.02 kcal
30 cal0.03 kcal
40 cal0.04 kcal
50 cal0.05 kcal
100 cal0.1 kcal
1000 cal1 kcal
10000 cal10 kcal