Attojoule is 1e-18 joule units.
Attojoules to Zeptojoules Converter — aJ to zJ
Convert Attojoule (aJ) to Zeptojoule (zJ) using the exact conversion factor (1 attojoule = 1,000 zeptojoule). See the formula, worked examples, and conversion table.
Attojoules to Zeptojoules converter
Converter
Engineering Converter
Convert common stress, force, torque, power, and energy units used in engineering.
Context values
Some unit families need one extra value for a physically accurate result.
Zeptojoule is 1e-21 joule units.
Result = input x 1e-18 / 1e-21.
Energy units are compatible.
Reserved above the conversion cards and below the converter.
About Converting Attojoules to Zeptojoules
Attojoule and Zeptojoule both measure a quantity used in structural or mechanical engineering — commonly stress, pressure, force, torque, power, or energy — where converting between the unit conventions used in different regions, industries, or equipment specifications is a routine part of design work. Specifically: Attojoule is 1e-18 joule units, and zeptojoule is 1e-21 joule units.
Formula
zeptojoules = attojoules × 1000
This factor comes from each unit's defined relationship to the category's base unit: 1 attojoule equals 1e-18 base units, and 1 zeptojoule equals 1e-21 base units, so dividing one by the other gives the direct attojoule-to-zeptojoule factor of 1000.
Simple example
1 aJ × 1000 = 1,000 zJ
1 attojoule = 1,000 zeptojoules.
Real-world example
100 aJ × 1000 = 100,000 zJ
100 attojoules = 100,000 zeptojoules.
Conversion table
| Attojoule (aJ) | Zeptojoule (zJ) |
|---|---|
| 1 aJ | 1,000 zJ |
| 10 aJ | 10,000 zJ |
| 50 aJ | 50,000 zJ |
| 100 aJ | 100,000 zJ |
| 500 aJ | 500,000 zJ |
| 1,000 aJ | 1,000,000 zJ |
Reverse conversion: Zeptojoule to Attojoule
1 zJ × 0.001 = 0.001 aJ
1 zeptojoule = 0.001 attojoules.
attojoules = zeptojoules × 0.001
For a page dedicated to this direction, see Zeptojoule to Attojoule.
Understanding the Attojoule (aJ)
Attojoule is 1e-18 joule units.
Understanding the Zeptojoule (zJ)
Zeptojoule is 1e-21 joule units.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many zeptojoules are in 1 attojoule?
1 attojoule equals 1,000 zeptojoules, using the exact defined conversion factor rather than an estimate.
How do I convert attojoule to zeptojoule?
Multiply the attojoule value by 1000. The converter above does this instantly to whatever precision you set.
How do I convert zeptojoule back to attojoule?
Use the reverse factor: 1 zeptojoule equals 0.001 attojoules. You can also use the swap control in the converter above to flip the direction instantly.
What is a attojoule?
Attojoule (aJ) is a unit of engineering.
What is a zeptojoule?
Zeptojoule (zJ) is a unit of engineering.
Is the attojoule to zeptojoule conversion exact?
Yes. Both attojoule and zeptojoule are defined by fixed standards rather than physical artifacts, so the factor of 1000 used above is exact to as many digits as you choose to display.
Why do engineering unit conventions vary so much by region and industry?
Pressure, force, and stress can be expressed in metric (pascal, newton), US customary (psi, pound-force), or older and industry-specific units (atmosphere, torr, kip) depending on the country, industry, and even the equipment manufacturer, which is why engineers routinely need to convert between them when working across specs from different sources.