Hectojoule is 100 joule units.
Hectojoules to Femtojoules Converter — hJ to fJ
Convert Hectojoule (hJ) to Femtojoule (fJ) using the exact conversion factor (1 hectojoule = 1e+17 femtojoule). See the formula, worked examples, and conversion table.
Hectojoules 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 100 / 1e-15.
Energy units are compatible.
Reserved above the conversion cards and below the converter.
About Converting Hectojoules to Femtojoules
Hectojoule 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: Hectojoule is 100 joule units, and femtojoule is 1e-15 joule units.
Formula
femtojoules = hectojoules × 1e+17
This factor comes from each unit's defined relationship to the category's base unit: 1 hectojoule equals 100 base units, and 1 femtojoule equals 1e-15 base units, so dividing one by the other gives the direct hectojoule-to-femtojoule factor of 1e+17.
Simple example
1 hJ × 1e+17 = 1e+17 fJ
1 hectojoule = 1e+17 femtojoules.
Real-world example
100 hJ × 1e+17 = 1e+19 fJ
100 hectojoules = 1e+19 femtojoules.
Conversion table
| Hectojoule (hJ) | Femtojoule (fJ) |
|---|---|
| 1 hJ | 1e+17 fJ |
| 10 hJ | 1e+18 fJ |
| 50 hJ | 5e+18 fJ |
| 100 hJ | 1e+19 fJ |
| 500 hJ | 5e+19 fJ |
| 1,000 hJ | 1e+20 fJ |
Reverse conversion: Femtojoule to Hectojoule
1e+17 fJ × 1e-17 = 1 hJ
1e+17 femtojoules = 1 hectojoules.
hectojoules = femtojoules × 1e-17
For a page dedicated to this direction, see Femtojoule to Hectojoule.
Understanding the Hectojoule (hJ)
Hectojoule is 100 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 hectojoule?
1 hectojoule equals 1e+17 femtojoules, using the exact defined conversion factor rather than an estimate.
How do I convert hectojoule to femtojoule?
Multiply the hectojoule value by 1e+17. The converter above does this instantly to whatever precision you set.
How do I convert femtojoule back to hectojoule?
Use the reverse factor: 1 femtojoule equals 1e-17 hectojoules. You can also use the swap control in the converter above to flip the direction instantly.
What is a hectojoule?
Hectojoule (hJ) is a unit of engineering.
What is a femtojoule?
Femtojoule (fJ) is a unit of engineering.
Is the hectojoule to femtojoule conversion exact?
Yes. Both hectojoule and femtojoule are defined by fixed standards rather than physical artifacts, so the factor of 1e+17 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.