Megajoule is 1000000 joule units.
Megajoules to Petajoules Converter — MJ to PJ
Convert Megajoule (MJ) to Petajoule (PJ) using the exact conversion factor (1 megajoule = 1e-9 petajoule). See the formula, worked examples, and conversion table.
Megajoules 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 Megajoules to Petajoules
Megajoule 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: Megajoule is 1000000 joule units, and petajoule is 1000000000000000 joule units.
Formula
petajoules = megajoules × 1e-9
This factor comes from each unit's defined relationship to the category's base unit: 1 megajoule equals 1000000 base units, and 1 petajoule equals 1e+15 base units, so dividing one by the other gives the direct megajoule-to-petajoule factor of 1e-9.
Simple example
1 MJ × 1e-9 = 1e-9 PJ
1 megajoule = 1e-9 petajoules.
Real-world example
100 MJ × 1e-9 = 1e-7 PJ
100 megajoules = 1e-7 petajoules.
Conversion table
| Megajoule (MJ) | Petajoule (PJ) |
|---|---|
| 1 MJ | 1e-9 PJ |
| 10 MJ | 1e-8 PJ |
| 50 MJ | 5e-8 PJ |
| 100 MJ | 1e-7 PJ |
| 500 MJ | 5e-7 PJ |
| 1,000 MJ | 0.000001 PJ |
Reverse conversion: Petajoule to Megajoule
1e-9 PJ × 1000000000 = 1 MJ
1e-9 petajoules = 1 megajoules.
megajoules = petajoules × 1000000000
For a page dedicated to this direction, see Petajoule to Megajoule.
Understanding the Megajoule (MJ)
Megajoule is 1000000 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 megajoule?
1 megajoule equals 1e-9 petajoules, using the exact defined conversion factor rather than an estimate.
How do I convert megajoule to petajoule?
Multiply the megajoule value by 1e-9. The converter above does this instantly to whatever precision you set.
How do I convert petajoule back to megajoule?
Use the reverse factor: 1 petajoule equals 1,000,000,000 megajoules. You can also use the swap control in the converter above to flip the direction instantly.
What is a megajoule?
Megajoule (MJ) is a unit of engineering.
What is a petajoule?
Petajoule (PJ) is a unit of engineering.
Is the megajoule to petajoule conversion exact?
Yes. Both megajoule and petajoule are defined by fixed standards rather than physical artifacts, so the factor of 1e-9 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.