gigajoule to megajoule
Convert gigajoule (GJ) to megajoule (MJ). Use an editable energy converter, conversion formula, and reference table.
1 GJ = 1,000 MJ
Conversion formula
One gigajoule equals 1,000 megajoule. Multiply your value in gigajoule by this factor to get megajoule. For the reverse conversion, divide by the same factor.
Worked example
To convert 5 gigajoule:5 × 1,000 = 5,000 MJ
Conversion table
| gigajoule (GJ) | megajoule (MJ) |
|---|---|
| 0.01 | 10 |
| 0.1 | 100 |
| 1 | 1,000 |
| 2 | 2,000 |
| 5 | 5,000 |
| 10 | 10,000 |
| 25 | 25,000 |
| 50 | 50,000 |
| 100 | 100,000 |
| 1000 | 1,000,000 |
About these measurements
Energy can be transferred through work, heating, or electrical processes.
The base reference used here is the joule. One gigajoule is 1,000,000,000 base units; one megajoule is 1,000,000 base units.
Important distinctions
Calorie and BTU definitions vary. These pages label thermochemical calories and International Table BTUs explicitly.
Precision
The converter uses stored conversion factors and floating-point arithmetic. Results display up to ten significant digits, switching to scientific notation for very small or large values. Keep the precision of your original measurement when reporting results.
Common questions
How do I convert GJ to MJ?
Multiply the quantity in GJ by 1,000. You can also type the value into the converter above.
Can I reverse the conversion?
Yes. Use the swap button or open the megajoule to gigajoule converter.
Reference
NIST Guide to the SI — conversion factors and prefix conventions. SI prefixes scale units by powers of ten; the dimension-specific notes above describe the assumptions used on this page.
