Femtojoule is 1e-15 joule units.
Femtojoules to Zeptojoules Converter — fJ to zJ
Convert Femtojoule (fJ) to Zeptojoule (zJ) using the exact conversion factor (1 femtojoule = 1,000,000 zeptojoule). See the formula, worked examples, and conversion table.
Femtojoules 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-15 / 1e-21.
Energy units are compatible.
Reserved above the conversion cards and below the converter.
About Converting Femtojoules to Zeptojoules
Femtojoule 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: Femtojoule is 1e-15 joule units, and zeptojoule is 1e-21 joule units.
Formula
zeptojoules = femtojoules × 1000000
This factor comes from each unit's defined relationship to the category's base unit: 1 femtojoule equals 1e-15 base units, and 1 zeptojoule equals 1e-21 base units, so dividing one by the other gives the direct femtojoule-to-zeptojoule factor of 1000000.
Simple example
1 fJ × 1000000 = 1,000,000 zJ
1 femtojoule = 1,000,000 zeptojoules.
Real-world example
100 fJ × 1000000 = 100,000,000 zJ
100 femtojoules = 100,000,000 zeptojoules.
Conversion table
| Femtojoule (fJ) | Zeptojoule (zJ) |
|---|---|
| 1 fJ | 1,000,000 zJ |
| 10 fJ | 10,000,000 zJ |
| 50 fJ | 50,000,000 zJ |
| 100 fJ | 100,000,000 zJ |
| 500 fJ | 500,000,000 zJ |
| 1,000 fJ | 1,000,000,000 zJ |
Reverse conversion: Zeptojoule to Femtojoule
1 zJ × 1e-6 = 1e-6 fJ
1 zeptojoule = 1e-6 femtojoules.
femtojoules = zeptojoules × 1e-6
For a page dedicated to this direction, see Zeptojoule to Femtojoule.
Understanding the Femtojoule (fJ)
Femtojoule is 1e-15 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 femtojoule?
1 femtojoule equals 1,000,000 zeptojoules, using the exact defined conversion factor rather than an estimate.
How do I convert femtojoule to zeptojoule?
Multiply the femtojoule value by 1000000. The converter above does this instantly to whatever precision you set.
How do I convert zeptojoule back to femtojoule?
Use the reverse factor: 1 zeptojoule equals 1e-6 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 zeptojoule?
Zeptojoule (zJ) is a unit of engineering.
Is the femtojoule to zeptojoule conversion exact?
Yes. Both femtojoule and zeptojoule are defined by fixed standards rather than physical artifacts, so the factor of 1000000 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.