Kilojoule is 1000 joule units.
Kilojoules to Kilocalories Converter — kJ to kcal
Convert Kilojoule (kJ) to Kilocalorie (kcal) using the exact conversion factor (1 kilojoule = 0.2390057361 kilocalorie). See the formula, worked examples, and conversion table.
Kilojoules to Kilocalories converter
Converter
Engineering Converter
Convert common stress, force, torque, power, and energy units used in engineering.
Context values
Some unit families need one extra value for a physically accurate result.
A kilocalorie is 1,000 calories.
Result = input x 1000 / 4184.
Energy units are compatible.
Reserved above the conversion cards and below the converter.
About Converting Kilojoules to Kilocalories
Kilojoule and Kilocalorie both measure a quantity used in structural or mechanical engineering — commonly stress, pressure, force, torque, power, or energy — where converting between the unit conventions used in different regions, industries, or equipment specifications is a routine part of design work. Specifically: Kilojoule is 1000 joule units, and a kilocalorie is 1,000 calories.
Formula
kilocalories = kilojoules × 0.239005736138
This factor comes from each unit's defined relationship to the category's base unit: 1 kilojoule equals 1000 base units, and 1 kilocalorie equals 4184 base units, so dividing one by the other gives the direct kilojoule-to-kilocalorie factor of 0.239005736138.
Simple example
1 kJ × 0.2390057361 = 0.2390057361 kcal
1 kilojoule = 0.2390057361 kilocalories.
Real-world example
100 kJ × 0.2390057361 = 23.90057361 kcal
100 kilojoules = 23.90057361 kilocalories.
Conversion table
| Kilojoule (kJ) | Kilocalorie (kcal) |
|---|---|
| 1 kJ | 0.2390057361 kcal |
| 10 kJ | 2.390057361 kcal |
| 50 kJ | 11.95028681 kcal |
| 100 kJ | 23.90057361 kcal |
| 500 kJ | 119.5028681 kcal |
| 1,000 kJ | 239.0057361 kcal |
Reverse conversion: Kilocalorie to Kilojoule
0.2390057361 kcal × 4.184 = 0.9999999998 kJ
0.2390057361 kilocalories = 0.9999999998 kilojoules.
kilojoules = kilocalories × 4.184
For a page dedicated to this direction, see Kilocalorie to Kilojoule.
Understanding the Kilojoule (kJ)
Kilojoule is 1000 joule units.
Understanding the Kilocalorie (kcal)
A kilocalorie is 1,000 calories.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many kilocalories are in 1 kilojoule?
1 kilojoule equals 0.2390057361 kilocalories, using the exact defined conversion factor rather than an estimate.
How do I convert kilojoule to kilocalorie?
Multiply the kilojoule value by 0.2390057361. The converter above does this instantly to whatever precision you set.
How do I convert kilocalorie back to kilojoule?
Use the reverse factor: 1 kilocalorie equals 4.184 kilojoules. You can also use the swap control in the converter above to flip the direction instantly.
What is a kilojoule?
Kilojoule (kJ) is a unit of engineering.
What is a kilocalorie?
Kilocalorie (kcal) is a unit of engineering.
Is the kilojoule to kilocalorie conversion exact?
Yes. Both kilojoule and kilocalorie are defined by fixed standards rather than physical artifacts, so the factor of 0.2390057361 used above is exact to as many digits as you choose to display.
Why do engineering unit conventions vary so much by region and industry?
Pressure, force, and stress can be expressed in metric (pascal, newton), US customary (psi, pound-force), or older and industry-specific units (atmosphere, torr, kip) depending on the country, industry, and even the equipment manufacturer, which is why engineers routinely need to convert between them when working across specs from different sources.