Calories (kcal) ⇄ Kilojoules (kJ) Converter
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Calories to Kilojoules
Using this tool
One Calorie (uppercase C) is the same as a kilocalorie, equal to 1000 calories in lowercase. This calculator allows you to shift between Calories and kilojoules, where 1 Calorie = 4.184 kilojoules, rounded to the nearest whole number.
This health calculator and converter offered by FatsReduce is built on credible medical research. Remember, it is not a diagnostic tool and cannot replace professional advice.
You should know
Food gives our bodies the nutrients and energy to function at both a physical and mental level, helping us feel happier and healthier. Knowing the value of foods lets you better understanding your intake and whether you consume more than needed, or how to compare one product with another.
Tracking calories can support healthy weight management within the right range. A balanced diet with vegetables, fruit, lean proteins, grains, and dairy (or alternatives) keeps energy steady. Reducing salt, sugar, saturated fats, and alcohol also helps maintain a healthy lifestyle.
Small & large calories
A small calorie (cal) measures the energy needed to increase the temperature of 1 gram of water by 1°C under 1 atmosphere of pressure.
A large calorie (Cal), equal to 1 kg of water raised by 1°C at 1 atmosphere, is also called a food calorie and is used as a standard unit of food energy.
Convert Calories to Kilojoules
In thermochemical terms:
1 calth = 0.004184 kJ and 1kJ= 239.005736 calth
E(kJ) = E(calth) / 239.005736
E(kJ) = 300cal15 / 238.9201 =1.25565kJ
For large/food Calories:
1 Cal = 4.184 kJ and 1kJ=0.239Cal
E(kJ) = 4.184 × E(Cal)
Example:
E(kJ) = 4.184×0.3Cal = 1.2552kJ
How many kilojoules are in one Calorie?
One Calorie equals 4.184 kilojoules, making it easy to measure food energy precisely.
Why do we convert Calories to kilojoules?
Converting helps align food energy with international standards and provides a clearer view of energy intake.
What is the difference between a small calorie and a large Calorie?
A small calorie measures the energy to heat 1 gram of water, while a large Calorie (food calorie) heats 1 kilogram of water.
How do I calculate kilojoules from Calories mathematically?
Use the formula:
E(kJ) = 4.184 × E(Cal)
Is FatsReduce’s Calories to Kilojoules converter reliable?
Yes, it is built on trusted medical research and designed for accurate, user-friendly conversions.
