A gigajoule (GJ) is a metric-prefixed unit of energy equal to 109 joules, using the SI giga prefix.
Gigajoules to Zeptojoules
Convert Gigajoule (GJ) to Zeptojoule (zJ) instantly with an exact formula, conversion table, and FAQ.
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Convert gigajoules (GJ) to zeptojoules (zJ) instantly with formula, conversion table, and FAQ.
Context values
Some unit families need one extra value for a physically accurate result.
A zeptojoule (zJ) is a metric-prefixed unit of energy equal to 10-21 joules, a fraction of a single joule, using the SI zepto prefix.
zJ = GJ × 1.000000000e+30
Results update instantly for Gigajoules to Zeptojoules conversions.
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Formula
zJ = GJ × 1.000000000e+30
GJ = zJ × 1.000000000e-30
Conversion table
| 1 GJ | 1.000000e+30 zJ |
| 5 GJ | 5.000000e+30 zJ |
| 10 GJ | 1.000000e+31 zJ |
| 20 GJ | 2.000000e+31 zJ |
| 50 GJ | 5.000000e+31 zJ |
| 100 GJ | 1.000000e+32 zJ |
| 500 GJ | 5.000000e+32 zJ |
| 1000 GJ | 1.000000e+33 zJ |
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How the formula works
Both gigajoule and zeptojoule measure the same physical quantity, so converting between them is a single multiplication. Multiply a value in gigajoules by 1.000000000e+30 to get zeptojoules. To reverse the conversion, multiply a zeptojoule value by 1.000000000e-30 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 Zeptojoule (zJ)?
A zeptojoule (zJ) is a metric-prefixed unit of energy equal to 10-21 joules, a fraction of a single joule, using the SI zepto prefix.
How do I convert gigajoules to zeptojoules?
Multiply the gigajoule value by 1.000000000e+30 to get the equivalent in zeptojoules. For example, 5 GJ × 1.000000000e+30 = 5.000000e+30 zJ.
Is this conversion exact?
Yes. Both units are defined against the SI base unit for this dimension, so the factor 1.000000000e+30 is an exact, non-rounded value.
Can I convert zeptojoules back to gigajoules?
Yes. Divide the zeptojoule value by 1.000000000e+30, or multiply it by 1.000000000e-30, to get gigajoules.
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About converting gigajoules to zeptojoules
A gigajoule (GJ) is a metric-prefixed unit of energy equal to 109 joules, using the SI giga prefix. A zeptojoule (zJ) is a metric-prefixed unit of energy equal to 10-21 joules, a fraction of a single joule, using the SI zepto prefix.
Use this calculator to move between gigajoules and zeptojoules accurately for homework, engineering, billing, or everyday energy calculations. The Universal Converter uses exact unit factors, so results stay consistent across the site.