A gigajoule (GJ) is a metric-prefixed unit of energy equal to 109 joules, using the SI giga prefix.
Gigajoules to Kilojoules
Convert Gigajoule (GJ) to Kilojoule (kJ) instantly with an exact formula, conversion table, and FAQ.
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Convert gigajoules (GJ) to kilojoules (kJ) instantly with formula, conversion table, and FAQ.
Context values
Some unit families need one extra value for a physically accurate result.
A kilojoule (kJ) equals 1,000 joules and is commonly used on nutrition labels outside the United States.
kJ = GJ × 1000000
Results update instantly for Gigajoules to Kilojoules conversions.
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Formula
kJ = GJ × 1000000
GJ = kJ × 0.000001
Conversion table
| 1 GJ | 1.000000e+06 kJ |
| 5 GJ | 5.000000e+06 kJ |
| 10 GJ | 1.000000e+07 kJ |
| 20 GJ | 2.000000e+07 kJ |
| 50 GJ | 5.000000e+07 kJ |
| 100 GJ | 1.000000e+08 kJ |
| 500 GJ | 5.000000e+08 kJ |
| 1000 GJ | 1.000000e+09 kJ |
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How the formula works
Both gigajoule and kilojoule measure the same physical quantity, so converting between them is a single multiplication. Multiply a value in gigajoules by 1000000 to get kilojoules. To reverse the conversion, multiply a kilojoule value by 0.000001 to get back to gigajoules.
Frequently asked questions
What is Gigajoule (GJ)?
A gigajoule (GJ) is a metric-prefixed unit of energy equal to 109 joules, using the SI giga prefix.
What is Kilojoule (kJ)?
A kilojoule (kJ) equals 1,000 joules and is commonly used on nutrition labels outside the United States.
How do I convert gigajoules to kilojoules?
Multiply the gigajoule value by 1000000 to get the equivalent in kilojoules. For example, 5 GJ × 1000000 = 5.000000e+06 kJ.
Is this conversion exact?
Yes. Both units are defined against the SI base unit for this dimension, so the factor 1000000 is an exact, non-rounded value.
Can I convert kilojoules back to gigajoules?
Yes. Divide the kilojoule value by 1000000, or multiply it by 0.000001, to get gigajoules.
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About converting gigajoules to kilojoules
A gigajoule (GJ) is a metric-prefixed unit of energy equal to 109 joules, using the SI giga prefix. A kilojoule (kJ) equals 1,000 joules and is commonly used on nutrition labels outside the United States.
Use this calculator to move between gigajoules and kilojoules accurately for homework, engineering, billing, or everyday energy calculations. The Universal Converter uses exact unit factors, so results stay consistent across the site.