Petajoule is 1000000000000000 joule units.
Petajoules to Megajoules Converter — PJ to MJ
Convert Petajoule (PJ) to Megajoule (MJ) using the exact conversion factor (1 petajoule = 1,000,000,000 megajoule). See the formula, worked examples, and conversion table.
Petajoules to Megajoules 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.
Megajoule is 1000000 joule units.
Result = input x 1e+15 / 1e+6.
Energy units are compatible.
Reserved above the conversion cards and below the converter.
About Converting Petajoules to Megajoules
Petajoule and Megajoule 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: Petajoule is 1000000000000000 joule units, and megajoule is 1000000 joule units.
Formula
megajoules = petajoules × 1000000000
This factor comes from each unit's defined relationship to the category's base unit: 1 petajoule equals 1e+15 base units, and 1 megajoule equals 1000000 base units, so dividing one by the other gives the direct petajoule-to-megajoule factor of 1000000000.
Simple example
1 PJ × 1000000000 = 1,000,000,000 MJ
1 petajoule = 1,000,000,000 megajoules.
Real-world example
100 PJ × 1000000000 = 100,000,000,000 MJ
100 petajoules = 100,000,000,000 megajoules.
Conversion table
| Petajoule (PJ) | Megajoule (MJ) |
|---|---|
| 1 PJ | 1,000,000,000 MJ |
| 10 PJ | 10,000,000,000 MJ |
| 50 PJ | 50,000,000,000 MJ |
| 100 PJ | 100,000,000,000 MJ |
| 500 PJ | 500,000,000,000 MJ |
| 1,000 PJ | 1e+12 MJ |
Reverse conversion: Megajoule to Petajoule
1 MJ × 1e-9 = 1e-9 PJ
1 megajoule = 1e-9 petajoules.
petajoules = megajoules × 1e-9
For a page dedicated to this direction, see Megajoule to Petajoule.
Understanding the Petajoule (PJ)
Petajoule is 1000000000000000 joule units.
Understanding the Megajoule (MJ)
Megajoule is 1000000 joule units.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many megajoules are in 1 petajoule?
1 petajoule equals 1,000,000,000 megajoules, using the exact defined conversion factor rather than an estimate.
How do I convert petajoule to megajoule?
Multiply the petajoule value by 1000000000. The converter above does this instantly to whatever precision you set.
How do I convert megajoule back to petajoule?
Use the reverse factor: 1 megajoule equals 1e-9 petajoules. You can also use the swap control in the converter above to flip the direction instantly.
What is a petajoule?
Petajoule (PJ) is a unit of engineering.
What is a megajoule?
Megajoule (MJ) is a unit of engineering.
Is the petajoule to megajoule conversion exact?
Yes. Both petajoule and megajoule are defined by fixed standards rather than physical artifacts, so the factor of 1000000000 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.