Convert Kilojoules to Calories
Convert Kilojoules to Calories instantly. 1 Kilojoule (kJ) equals 239.0057 Calories (cal).
Kilojoules to Calories conversion table
| Kilojoules (kJ) | Calories (cal) |
|---|---|
| 1 kJ | 239.0057 cal |
| 2 kJ | 478.0115 cal |
| 3 kJ | 717.0172 cal |
| 5 kJ | 1,195.03 cal |
| 10 kJ | 2,390.06 cal |
| 20 kJ | 4,780.11 cal |
| 50 kJ | 11,950.29 cal |
| 100 kJ | 23,900.57 cal |
| 500 kJ | 119,502.87 cal |
| 1,000 kJ | 239,005.74 cal |
1 Kilojoule = 239.0057 Calories · multiply Kilojoules by 239.0057
About converting Kilojoules to Calories
Kilojoules (kJ) and Calories (cal) are both units of energy, so converting between them is a single multiplication: multiply your Kilojoules figure by 239.0057. Ten Kilojoules comes to 2,390.06 Calories, and a hundred works out at 23,900.57 Calories.
Rule of thumb: going from Kilojoules to Calories multiplies, so the figure always grows — one Kilojoule is already 239.0057 Calories. If your answer came out smaller, you have the conversion the wrong way round.
What is a Kilojoule?
A kilojoule is a thousand joules, the size at which the joule becomes practical for everyday quantities. In Australia and New Zealand it is the primary unit on nutrition labels — food energy is quoted in kilojoules first, with calories relegated to a secondary figure or dropped entirely — so shoppers there think about daily intake in thousands of kilojoules rather than thousands of calories. It is also the working unit of chemistry, where reaction and bond energies are tabulated per mole. European labels print both kJ and kcal, which is why the same packet carries two different numbers for the same food.
What is a Calory?
The calorie is the unit most likely to be misread, because there are two of them. The small calorie — the one this converter uses — is approximately the heat needed to warm a gram of water by one degree Celsius, and it is a tiny amount of energy. The "calories" printed on food labels are not these: a food Calorie, traditionally written with a capital C, is a thousand small calories, properly a kilocalorie. So a 2,000-calorie daily diet is really about 8.4 million small calories. Several slightly different calories were defined historically; the thermochemical calorie used here is fixed at exactly 4.184 joules.
To put both in perspective: a slice of bread carries roughly 300 kilojoules, while an apple holds roughly 95,000 small calories.
The converter above updates as you type, and the table lists common values for quick reference. Need the opposite direction? Use the Calories to Kilojoules converter, or browse all Energy converters.
Frequently asked questions
How many Calories are in one Kilojoule?
There are 239.0057 Calories in one Kilojoule.
How do I convert Kilojoules to Calories?
Multiply the number of Kilojoules by 239.0057. For example, 10 Kilojoules = 2,390.06 Calories.
What is 100 Kilojoules in Calories?
100 Kilojoules is equal to 23,900.57 Calories.
How do I convert Calories to Kilojoules?
Multiply the Calories value by 0.004184 (or divide by 239.0057).
Is this Kilojoules to Calories conversion exact?
The definition is exact — Kilojoules and Calories are both fixed against the same base by international agreement — but the decimal shown here is rounded for readability, because the true ratio does not terminate. For engineering or scientific work, carry more decimal places than this page displays.
What is a Kilojoule?
A kilojoule is a thousand joules, the size at which the joule becomes practical for everyday quantities. In Australia and New Zealand it is the primary unit on nutrition labels — food energy is quoted in kilojoules first, with calories relegated to a secondary figure or dropped entirely — so shoppers there think about daily intake in thousands of kilojoules rather than thousands of calories. It is also the working unit of chemistry, where reaction and bond energies are tabulated per mole. European labels print both kJ and kcal, which is why the same packet carries two different numbers for the same food.
What is a Calory?
The calorie is the unit most likely to be misread, because there are two of them. The small calorie — the one this converter uses — is approximately the heat needed to warm a gram of water by one degree Celsius, and it is a tiny amount of energy. The "calories" printed on food labels are not these: a food Calorie, traditionally written with a capital C, is a thousand small calories, properly a kilocalorie. So a 2,000-calorie daily diet is really about 8.4 million small calories. Several slightly different calories were defined historically; the thermochemical calorie used here is fixed at exactly 4.184 joules.