Gigajoule is 1000000000 joule units.
Gigajoules to Terajoules Converter — GJ to TJ
Convert Gigajoule (GJ) to Terajoule (TJ) using the exact conversion factor (1 gigajoule = 0.001 terajoule). See the formula, worked examples, and conversion table.
Gigajoules to Terajoules 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.
Terajoule is 1000000000000 joule units.
Result = input x 1e+9 / 1e+12.
Energy units are compatible.
Reserved above the conversion cards and below the converter.
About Converting Gigajoules to Terajoules
Gigajoule and Terajoule 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 terajoule is 1000000000000 joule units.
Formula
terajoules = gigajoules × 0.001
This factor comes from each unit's defined relationship to the category's base unit: 1 gigajoule equals 1000000000 base units, and 1 terajoule equals 1e+12 base units, so dividing one by the other gives the direct gigajoule-to-terajoule factor of 0.001.
Simple example
1 GJ × 0.001 = 0.001 TJ
1 gigajoule = 0.001 terajoules.
Real-world example
100 GJ × 0.001 = 0.1 TJ
100 gigajoules = 0.1 terajoules.
Conversion table
| Gigajoule (GJ) | Terajoule (TJ) |
|---|---|
| 1 GJ | 0.001 TJ |
| 10 GJ | 0.01 TJ |
| 50 GJ | 0.05 TJ |
| 100 GJ | 0.1 TJ |
| 500 GJ | 0.5 TJ |
| 1,000 GJ | 1 TJ |
Reverse conversion: Terajoule to Gigajoule
0.001 TJ × 1000 = 1 GJ
0.001 terajoules = 1 gigajoule.
gigajoules = terajoules × 1000
For a page dedicated to this direction, see Terajoule to Gigajoule.
Understanding the Gigajoule (GJ)
Gigajoule is 1000000000 joule units.
Understanding the Terajoule (TJ)
Terajoule is 1000000000000 joule units.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many terajoules are in 1 gigajoule?
1 gigajoule equals 0.001 terajoules, using the exact defined conversion factor rather than an estimate.
How do I convert gigajoule to terajoule?
Multiply the gigajoule value by 0.001. The converter above does this instantly to whatever precision you set.
How do I convert terajoule back to gigajoule?
Use the reverse factor: 1 terajoule equals 1,000 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 terajoule?
Terajoule (TJ) is a unit of engineering.
Is the gigajoule to terajoule conversion exact?
Yes. Both gigajoule and terajoule 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.