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.
Joules to Zeptojoules
Convert Joule (J) to Zeptojoule (zJ) instantly with an exact formula, conversion table, and FAQ.
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Convert joules (J) 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 = J × 1.000000000e+21
Results update instantly for Joules to Zeptojoules conversions.
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Formula
zJ = J × 1.000000000e+21
J = zJ × 1.000000000e-21
Conversion table
| 1 J | 1.000000e+21 zJ |
| 5 J | 5.000000e+21 zJ |
| 10 J | 1.000000e+22 zJ |
| 20 J | 2.000000e+22 zJ |
| 50 J | 5.000000e+22 zJ |
| 100 J | 1.000000e+23 zJ |
| 500 J | 5.000000e+23 zJ |
| 1000 J | 1.000000e+24 zJ |
Related conversions
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How the formula works
Both joule and zeptojoule measure the same physical quantity, so converting between them is a single multiplication. Multiply a value in joules by 1.000000000e+21 to get zeptojoules. To reverse the conversion, multiply a zeptojoule value by 1.000000000e-21 to get back to joules.
Frequently asked questions
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.
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 joules to zeptojoules?
Multiply the joule value by 1.000000000e+21 to get the equivalent in zeptojoules. For example, 5 J × 1.000000000e+21 = 5.000000e+21 zJ.
Is this conversion exact?
Yes. Both units are defined against the SI base unit for this dimension, so the factor 1.000000000e+21 is an exact, non-rounded value.
Can I convert zeptojoules back to joules?
Yes. Divide the zeptojoule value by 1.000000000e+21, or multiply it by 1.000000000e-21, to get joules.
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About converting joules to zeptojoules
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. 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 joules 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.