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 Attojoules
Convert Joule (J) to Attojoule (aJ) 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 joules (J) to attojoules (aJ) instantly with formula, conversion table, and FAQ.
Context values
Some unit families need one extra value for a physically accurate result.
A attojoule (aJ) is a metric-prefixed unit of energy equal to 10-18 joules, a fraction of a single joule, using the SI atto prefix.
aJ = J × 1.000000000e+18
Results update instantly for Joules to Attojoules conversions.
Reserved above the conversion cards and below the converter.
Formula
aJ = J × 1.000000000e+18
J = aJ × 1.000000000e-18
Conversion table
| 1 J | 1.000000e+18 aJ |
| 5 J | 5.000000e+18 aJ |
| 10 J | 1.000000e+19 aJ |
| 20 J | 2.000000e+19 aJ |
| 50 J | 5.000000e+19 aJ |
| 100 J | 1.000000e+20 aJ |
| 500 J | 5.000000e+20 aJ |
| 1000 J | 1.000000e+21 aJ |
Related conversions
Reserved between the cards and the FAQ so the page stays balanced.
How the formula works
Both joule and attojoule measure the same physical quantity, so converting between them is a single multiplication. Multiply a value in joules by 1.000000000e+18 to get attojoules. To reverse the conversion, multiply a attojoule value by 1.000000000e-18 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 Attojoule (aJ)?
A attojoule (aJ) is a metric-prefixed unit of energy equal to 10-18 joules, a fraction of a single joule, using the SI atto prefix.
How do I convert joules to attojoules?
Multiply the joule value by 1.000000000e+18 to get the equivalent in attojoules. For example, 5 J × 1.000000000e+18 = 5.000000e+18 aJ.
Is this conversion exact?
Yes. Both units are defined against the SI base unit for this dimension, so the factor 1.000000000e+18 is an exact, non-rounded value.
Can I convert attojoules back to joules?
Yes. Divide the attojoule value by 1.000000000e+18, or multiply it by 1.000000000e-18, to get joules.
Reserved between the FAQ and the article so the page stays balanced.
About converting joules to attojoules
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 attojoule (aJ) is a metric-prefixed unit of energy equal to 10-18 joules, a fraction of a single joule, using the SI atto prefix.
Use this calculator to move between joules and attojoules accurately for homework, engineering, billing, or everyday energy calculations. The Universal Converter uses exact unit factors, so results stay consistent across the site.