Kcal vs. Cal – What Is the Difference?

What Is the Difference Between Calories and Kilocalories?

1 Kcal (kilocalorie) equals 1 Cal (large calorie). Both a kilocalorie (kcal) and a large Calorie (capital C) signify units of energy and are the same in terms of energy content. When the word calorie is written with a lowercase “c,” it technically refers to small calories, where 1 kcal or 1 Calorie equals 1,000 small calories. [1]

In a nutshell: 1 kcal = 1 Cal = 1,000 cal

But why do so many of us get confused by those two terms?

Units and scales are at the core of the confusion between the difference between cal and kcal. Another source of confusion lies in language and labeling. In many countries, especially the United States, the term “calorie” is used on food labels and in dietary guidelines when they, in fact, refer to “kilocalories/kcal.” But why do they do this?

This practice stems from a desire to simplify the terminology for the public by omitting the prefix “k,” which stands for kilo. “Kilo” implies a multiplier of 1,000. This principle mirrors the relationship between a kilogram and its base unit, the gram, where 1 kilogram equals 1,000 grams. [1]

Since nowadays, the words “Calories” and “kcal” are used interchangeably, both denoting the same amount of energy concerning food, there's no need to convert them, as 1 kilocalorie equals 1 Calorie in the context of nutrition and food labels. This is supported by the US FDA and the US Department of Agriculture, stating that the term “calories” when talking about food indeed refers to Kcal. [2] [3]

So, when you read about a calorie on food labels (nutrition facts label), it's technically kilocalories, indicating the energy content available to your body from eating that food.

And what exactly are a Kcal and Calorie?

Both Kcal and a large Calorie refer to the heat required to raise the temperature of one kilogram of water by one degree Celsius.

A small calorie (cal) is a unit of energy that is defined as the amount of heat needed to raise the temperature of one gram of water by one degree Celsius.

How to Convert Kcal into Calories?

Remember, if you read about kcal vs. calories in food, they both mean kcal. Usually, there is no need to convert them.

Still, converting kilocalories to small calories (lowercase “c”) is straightforward once you understand the relationship between the two. Since 1 kcal equals 1,000 small calories, you simply multiply the number of kilocalories by 1,000.

Let's take a look at this in one example:

Two bananas contain approximately 250 kcal (250 Calories), which is 250,000 small calories.

250 kcal * 1,000 = 250,000 cal

How to Convert Calories Into Kilojoules?

While Calories and kilocalories are common in the United States, many other countries use the joule (J) or kilojoule (kJ) as a unit of energy, especially on food labels.

To convert Calories to kilojoules, you use the conversion factor, where 1 Calorie equals approximately 4.184 joules. You will most probably need a calculator to do that. [4]

Example:

A full serving of bulgur salad contains approximately 500 Calories (or 500 kcal), about 2,092 kilojoules.

500 kcal * 4.184 = 2,092 kJ

Where Do You Find Calories on Food Labels?

Food labels provide crucial information about the energy and nutrition content of food items worldwide. The energy content is typically listed under a section marked “Energy” or “Nutrition facts.”

In countries that use calories, this will be listed as Calories (or kcal), while in many other places, you'll find this information given in kilojoules (kJ).

Regardless of the unit, this information is meant to help you understand how much energy you're getting from a serving of any food product, helping you manage your overall energy intake.

Just look for the term Calorie, kcal, or kJ on the nutrition label.

How Many Calories Do You Burn Per Day?

The number of calories you burn daily, known as your Total Daily Energy Expenditure (TDEE), varies significantly based on your age, sex, weight, height, and level of physical activity.

On average, adult men require about 2,500 kcal per day, while adult women need about 2,000 kcal. [1] [5]

However, these are rough estimates, and your specific needs may vary. Tools and calculators that can provide a more personalized estimate by considering your unique factors are available online.

CARE has prepared a general overview of energy consumption based on gender, age, and activity levels. These estimates provide you with a general framework to understand how many calories (kcal) and kilojoules (kJ) men and women might burn per day, depending on their age and how active they are. [1]

Please remember that these are approximations, and your needs can vary based on factors like muscle mass, metabolic health, and more.

Men – Estimate of Energy Needs per Day

18–30 Years

• Sedentary: 2,400 kcal (10,041 kJ) — 2,600 kcal (10,878 kJ)
• Moderately Active: 2,600 kcal (10,878 kJ) — 2,800 kcal (11,715 kJ)
• Active: 3,000 kcal (12,552 kJ) — 3,200 kcal (13,389 kJ)

31–50 Years

• Sedentary: 2,200 kcal (9,205 kJ) — 2,400 kcal (10,041 kJ)
• Moderately Active: 2,400 kcal (10,041 kJ) — 2,600 kcal (10,878 kJ)
• Active: 2,800 kcal (11,715 kJ) — 3,000 kcal (12,552 kJ)

51+ Years

• Sedentary: 2,000 kcal (8,368 kJ) — 2,200 kcal (9,205 kJ)
• Moderately Active: 2,200 kcal (9,205 kJ) — 2,400 kcal (10,041 kJ)
• Active: 2,400 kcal (10,041 kJ) — 2,800 kcal (11,715 kJ)

Women – Estimate of Energy Needs per Day

18–30 Years

• Sedentary: 1,800 kcal (7,531 kJ) — 2,000 kcal (8,368 kJ)
• Moderately Active: 2,000 kcal (8,368 kJ) — 2,200 kcal (9,205 kJ)
• Active: 2,400 kcal (10,041 kJ) — 2,600 kcal (10,878 kJ)

31–50 Years

• Sedentary: 1,800 kcal (7,531 kJ) — 1,900 kcal (7,949 kJ)
• Moderately Active: 2,000 kcal (8,368 kJ) — 2,200 kcal (9,205 kJ)
• Active: 2,200 kcal (9,205 kJ) — 2,400 kcal (10,041 kJ)

51+ Years

• Sedentary: 1,600 kcal (6,694 kJ) — 1,800 kcal (7,531 kJ)
• Moderately Active: 1,800 kcal (7,531 kJ) — 2,000 kcal (8,368 kJ)
• Active: 2,000 kcal (8,368 kJ) — 2,200 kcal (9,205 kJ)

How Many Calories for Weight Loss?

If you want to lose weight or achieve a healthy weight, you need to create an energy deficit, meaning you consume fewer calories than your body burns. A general guideline is to reduce your calorie intake by 500-1,000 kcal to lose about 1–2 pounds (approximately 0.5-1 kg) per week. [1]

Please approach your calorie deficit to achieve weight loss in a healthy, sustainable manner, focusing on nutritious foods and maintaining a balanced diet with macronutrients rather than merely cutting calories and counting calories excessively. Consulting a healthcare provider or a nutritionist can help you plan an effective and safe weight-loss strategy.