Gigajoule is 1000000000 joule units.
Gigajoules to Attojoules Converter — GJ to aJ
Convert Gigajoule (GJ) to Attojoule (aJ) using the exact conversion factor (1 gigajoule = 1e+27 attojoule). See the formula, worked examples, and conversion table.
Gigajoules 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+9 / 1e-18.
Energy units are compatible.
Reserved above the conversion cards and below the converter.
About Converting Gigajoules to Attojoules
Gigajoule 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: Gigajoule is 1000000000 joule units, and attojoule is 1e-18 joule units.
Formula
attojoules = gigajoules × 1e+27
This factor comes from each unit's defined relationship to the category's base unit: 1 gigajoule equals 1000000000 base units, and 1 attojoule equals 1e-18 base units, so dividing one by the other gives the direct gigajoule-to-attojoule factor of 1e+27.
Simple example
1 GJ × 1e+27 = 1e+27 aJ
1 gigajoule = 1e+27 attojoules.
Real-world example
100 GJ × 1e+27 = 1e+29 aJ
100 gigajoules = 1e+29 attojoules.
Conversion table
| Gigajoule (GJ) | Attojoule (aJ) |
|---|---|
| 1 GJ | 1e+27 aJ |
| 10 GJ | 1e+28 aJ |
| 50 GJ | 5e+28 aJ |
| 100 GJ | 1e+29 aJ |
| 500 GJ | 5e+29 aJ |
| 1,000 GJ | 1e+30 aJ |
Reverse conversion: Attojoule to Gigajoule
1e+27 aJ × 1e-27 = 1 GJ
1e+27 attojoules = 1 gigajoules.
gigajoules = attojoules × 1e-27
For a page dedicated to this direction, see Attojoule to Gigajoule.
Understanding the Gigajoule (GJ)
Gigajoule is 1000000000 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 gigajoule?
1 gigajoule equals 1e+27 attojoules, using the exact defined conversion factor rather than an estimate.
How do I convert gigajoule to attojoule?
Multiply the gigajoule value by 1e+27. The converter above does this instantly to whatever precision you set.
How do I convert attojoule back to gigajoule?
Use the reverse factor: 1 attojoule equals 1e-27 gigajoules. You can also use the swap control in the converter above to flip the direction instantly.
What is a gigajoule?
Gigajoule (GJ) is a unit of engineering.
What is a attojoule?
Attojoule (aJ) is a unit of engineering.
Is the gigajoule to attojoule conversion exact?
Yes. Both gigajoule and attojoule are defined by fixed standards rather than physical artifacts, so the factor of 1e+27 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.