Attojoule is 1e-18 joule units.
Attojoules to Femtojoules Converter — aJ to fJ
Convert Attojoule (aJ) to Femtojoule (fJ) using the exact conversion factor (1 attojoule = 0.001 femtojoule). See the formula, worked examples, and conversion table.
Attojoules to Femtojoules 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.
Femtojoule is 1e-15 joule units.
Result = input x 1e-18 / 1e-15.
Energy units are compatible.
Reserved above the conversion cards and below the converter.
About Converting Attojoules to Femtojoules
Attojoule and Femtojoule 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 femtojoule is 1e-15 joule units.
Formula
femtojoules = attojoules × 0.001
This factor comes from each unit's defined relationship to the category's base unit: 1 attojoule equals 1e-18 base units, and 1 femtojoule equals 1e-15 base units, so dividing one by the other gives the direct attojoule-to-femtojoule factor of 0.001.
Simple example
1 aJ × 0.001 = 0.001 fJ
1 attojoule = 0.001 femtojoules.
Real-world example
100 aJ × 0.001 = 0.1 fJ
100 attojoules = 0.1 femtojoules.
Conversion table
| Attojoule (aJ) | Femtojoule (fJ) |
|---|---|
| 1 aJ | 0.001 fJ |
| 10 aJ | 0.01 fJ |
| 50 aJ | 0.05 fJ |
| 100 aJ | 0.1 fJ |
| 500 aJ | 0.5 fJ |
| 1,000 aJ | 1 fJ |
Reverse conversion: Femtojoule to Attojoule
0.001 fJ × 1000 = 1 aJ
0.001 femtojoules = 1 attojoule.
attojoules = femtojoules × 1000
For a page dedicated to this direction, see Femtojoule to Attojoule.
Understanding the Attojoule (aJ)
Attojoule is 1e-18 joule units.
Understanding the Femtojoule (fJ)
Femtojoule is 1e-15 joule units.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many femtojoules are in 1 attojoule?
1 attojoule equals 0.001 femtojoules, using the exact defined conversion factor rather than an estimate.
How do I convert attojoule to femtojoule?
Multiply the attojoule value by 0.001. The converter above does this instantly to whatever precision you set.
How do I convert femtojoule back to attojoule?
Use the reverse factor: 1 femtojoule equals 1,000 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 femtojoule?
Femtojoule (fJ) is a unit of engineering.
Is the attojoule to femtojoule conversion exact?
Yes. Both attojoule and femtojoule are defined by fixed standards rather than physical artifacts, so the factor of 0.001 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.