Converting kJ/kcal - How to convert kJ and kcal (calculator)

Calculator: how to convert kJ and kcal?

When calculating the energy we supply to the body, we can be guided by two units: calories and joules. More precisely, kilocalories and kilojoules.

We have already encountered both units.

Every day we see these values on food packaging. They are provided for the use of consumers. They inform them about nutritional data (protein, fat, sugars) and energy values.

The energy value must be given in both kJ (kilojoules) and kcal (kilocalories).

Labelling is mandatory.

They are kilocalories - although in everyday life we refer to them as calories.

What is the meaning of these values for the average consumer?

The human body needs to take in nutrients and energy from conception. They are essential for the proper functioning of the body.

The body has a basic energy requirement even when inactive (lying down, sleeping, not thinking).

It gets energy from food in the form of proteins, fats and sugars.

In addition to these basic nutrients, we also need important vitamins and minerals and water.

But back to energy.

Energy can be expressed in two values:

• Kilocalorie = kcal (1 kcal = 1000 cal)
• Kilojoules = kJ (1 kJ = 1000 J)

When converting between units, we can use a simple formula. 1 kilocalorie equals 4.184 kilojoules.

Conversion between kcal and kJ:

• 1 kcal = 4.184 kJ
• 1 kJ = 0.2388 kcal
• Kilocalorie = 4184 J

For a rough calculation, just remember that 1 kcal is approximately 4.2 kJ.

To make it easier, you can calculate the conversion in our calculator.

And what are calories and joules?

A calorie defines how much energy must be given to one gram of water to raise its temperature from 14.5 °C to 15.5 °C.

A joule is a unit of work and energy.

One joule is equal to the kinetic energy of a kilogram of mass moving at a speed of one metre per second. One joule is equal to work equal to 1 newton applied to a body following a path of one metre.

Complicated. But for ease of understanding...

An adult male should take in approximately 9,200 to 10,050 kJ = 2,198 to 2,402 kcal of energy during a day of normal activity.

Women should take in approximately 7530 to 8370 kJ = 1799-2000 kcal.

The basal energy requirement is about 65% of the total energy expenditure. The body needs energy to maintain basic life functions at rest.

We are all different. This should be taken into account in energy calculations. Height, weight and age are taken into account in the calculations.

What happens to the remaining 35 percent of energy?

About 10 percent goes into food processing and about 25 percent into physical activity.

Our body is energy dependent. It needs to be supplied with a total amount of energy.

And we all know this.

When we eat too much food, energy is stored and we gain weight.

When food is scarce, we lose weight.

The rational thing to do is to be somewhere in the middle and have a balanced daily energy intake and expenditure.

You can also find interesting information on the topic in the articles:

• Essential nutrients in the human diet: what are proteins, sugars, fats?
• Calorie tables.
• BMI: How to calculate body mass index?
• BMR Calculator - Basal Metabolic Rate
• Healthy weight loss for women: Appropriate diet and exercise. Truths and myths about weight loss