A kilocalorie (kcal) equals 1,000 small calories and is the unit behind the food "Calorie" shown on nutrition labels.
Kilocalories to Gigajoules
Convert Kilocalorie (kcal) to Gigajoule (GJ) instantly with an exact formula, conversion table, and FAQ.
Reserved for a responsive leaderboard above the conversion details.
Professional calculator style
World-scale conversion engine
30+ categories
6,500+ units
Instant results
Offline ready
Energy calculator
Energy Converter
Convert kilocalories (kcal) to gigajoules (GJ) instantly with formula, conversion table, and FAQ.
Context values
Some unit families need one extra value for a physically accurate result.
A gigajoule (GJ) is a metric-prefixed unit of energy equal to 109 joules, using the SI giga prefix.
GJ = kcal × 0.000004184
Results update instantly for Kilocalories to Gigajoules conversions.
Reserved above the conversion cards and below the converter.
Formula
GJ = kcal × 0.000004184
kcal = GJ × 239005.7361
Conversion table
| 1 kcal | 0.000004 GJ |
| 5 kcal | 0.000021 GJ |
| 10 kcal | 0.000042 GJ |
| 20 kcal | 0.000084 GJ |
| 50 kcal | 0.000209 GJ |
| 100 kcal | 0.000418 GJ |
| 500 kcal | 0.002092 GJ |
| 1000 kcal | 0.004184 GJ |
Related conversions
Reserved between the cards and the FAQ so the page stays balanced.
How the formula works
Both kilocalorie and gigajoule measure the same physical quantity, so converting between them is a single multiplication. Multiply a value in kilocalories by 0.000004184 to get gigajoules. To reverse the conversion, multiply a gigajoule value by 239005.7361 to get back to kilocalories.
Frequently asked questions
What is Kilocalorie (kcal)?
A kilocalorie (kcal) equals 1,000 small calories and is the unit behind the food "Calorie" shown on nutrition labels.
What is Gigajoule (GJ)?
A gigajoule (GJ) is a metric-prefixed unit of energy equal to 109 joules, using the SI giga prefix.
How do I convert kilocalories to gigajoules?
Multiply the kilocalorie value by 0.000004184 to get the equivalent in gigajoules. For example, 5 kcal × 0.000004184 = 0.000021 GJ.
Is this conversion exact?
Yes. Both units are defined against the SI base unit for this dimension, so the factor 0.000004184 is an exact, non-rounded value.
Can I convert gigajoules back to kilocalories?
Yes. Divide the gigajoule value by 0.000004184, or multiply it by 239005.7361, to get kilocalories.
Reserved between the FAQ and the article so the page stays balanced.
About converting kilocalories to gigajoules
A kilocalorie (kcal) equals 1,000 small calories and is the unit behind the food "Calorie" shown on nutrition labels. A gigajoule (GJ) is a metric-prefixed unit of energy equal to 109 joules, using the SI giga prefix.
Use this calculator to move between kilocalories and gigajoules accurately for homework, engineering, billing, or everyday energy calculations. The Universal Converter uses exact unit factors, so results stay consistent across the site.