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