Microjoule is 0.000001 joule units.
Microjoules to Petajoules Converter — uJ to PJ
Convert Microjoule (uJ) to Petajoule (PJ) using the exact conversion factor (1 microjoule = 1e-21 petajoule). See the formula, worked examples, and conversion table.
Microjoules to Petajoules 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.
Petajoule is 1000000000000000 joule units.
Result = input x 1e-6 / 1e+15.
Energy units are compatible.
Reserved above the conversion cards and below the converter.
About Converting Microjoules to Petajoules
Microjoule and Petajoule 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: Microjoule is 0.000001 joule units, and petajoule is 1000000000000000 joule units.
Formula
petajoules = microjoules × 1e-21
This factor comes from each unit's defined relationship to the category's base unit: 1 microjoule equals 0.000001 base units, and 1 petajoule equals 1e+15 base units, so dividing one by the other gives the direct microjoule-to-petajoule factor of 1e-21.
Simple example
1 uJ × 1e-21 = 1e-21 PJ
1 microjoule = 1e-21 petajoules.
Real-world example
100 uJ × 1e-21 = 1e-19 PJ
100 microjoules = 1e-19 petajoules.
Conversion table
| Microjoule (uJ) | Petajoule (PJ) |
|---|---|
| 1 uJ | 1e-21 PJ |
| 10 uJ | 1e-20 PJ |
| 50 uJ | 5e-20 PJ |
| 100 uJ | 1e-19 PJ |
| 500 uJ | 5e-19 PJ |
| 1,000 uJ | 1e-18 PJ |
Reverse conversion: Petajoule to Microjoule
1e-21 PJ × 1e+21 = 1 uJ
1e-21 petajoules = 1 microjoule.
microjoules = petajoules × 1e+21
For a page dedicated to this direction, see Petajoule to Microjoule.
Understanding the Microjoule (uJ)
Microjoule is 0.000001 joule units.
Understanding the Petajoule (PJ)
Petajoule is 1000000000000000 joule units.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many petajoules are in 1 microjoule?
1 microjoule equals 1e-21 petajoules, using the exact defined conversion factor rather than an estimate.
How do I convert microjoule to petajoule?
Multiply the microjoule value by 1e-21. The converter above does this instantly to whatever precision you set.
How do I convert petajoule back to microjoule?
Use the reverse factor: 1 petajoule equals 1e+21 microjoules. You can also use the swap control in the converter above to flip the direction instantly.
What is a microjoule?
Microjoule (uJ) is a unit of engineering.
What is a petajoule?
Petajoule (PJ) is a unit of engineering.
Is the microjoule to petajoule conversion exact?
Yes. Both microjoule and petajoule are defined by fixed standards rather than physical artifacts, so the factor of 1e-21 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.