A gigajoule (GJ) is a metric-prefixed unit of energy equal to 109 joules, using the SI giga prefix.
Gigajoules to Joules
Convert Gigajoule (GJ) to Joule (J) 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 gigajoules (GJ) to joules (J) instantly with formula, conversion table, and FAQ.
Context values
Some unit families need one extra value for a physically accurate result.
The joule (J) is the SI derived unit of energy, equal to the work done when a force of one newton acts over one meter.
J = GJ × 1000000000
Results update instantly for Gigajoules to Joules conversions.
Reserved above the conversion cards and below the converter.
Formula
J = GJ × 1000000000
GJ = J × 1.000000000e-09
Conversion table
| 1 GJ | 1.000000e+09 J |
| 5 GJ | 5.000000e+09 J |
| 10 GJ | 1.000000e+10 J |
| 20 GJ | 2.000000e+10 J |
| 50 GJ | 5.000000e+10 J |
| 100 GJ | 1.000000e+11 J |
| 500 GJ | 5.000000e+11 J |
| 1000 GJ | 1.000000e+12 J |
Related conversions
Reserved between the cards and the FAQ so the page stays balanced.
How the formula works
Both gigajoule and joule measure the same physical quantity, so converting between them is a single multiplication. Multiply a value in gigajoules by 1000000000 to get joules. To reverse the conversion, multiply a joule value by 1.000000000e-09 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 Joule (J)?
The joule (J) is the SI derived unit of energy, equal to the work done when a force of one newton acts over one meter.
How do I convert gigajoules to joules?
Multiply the gigajoule value by 1000000000 to get the equivalent in joules. For example, 5 GJ × 1000000000 = 5.000000e+09 J.
Is this conversion exact?
Yes. Both units are defined against the SI base unit for this dimension, so the factor 1000000000 is an exact, non-rounded value.
Can I convert joules back to gigajoules?
Yes. Divide the joule value by 1000000000, or multiply it by 1.000000000e-09, to get gigajoules.
Reserved between the FAQ and the article so the page stays balanced.
About converting gigajoules to joules
A gigajoule (GJ) is a metric-prefixed unit of energy equal to 109 joules, using the SI giga prefix. The joule (J) is the SI derived unit of energy, equal to the work done when a force of one newton acts over one meter.
Use this calculator to move between gigajoules and joules accurately for homework, engineering, billing, or everyday energy calculations. The Universal Converter uses exact unit factors, so results stay consistent across the site.