Convert Megajoules to Joules (MJ to J)
1 megajoule (MJ) equals 1000000 joules (J).
1 MJ = 1000000 J
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk megajoule to joule converter to paste a column from Excel.
How to Convert Megajoule to Joule
- 1 MJ = 1000000 J
- 1 J = 0.000001 MJ
- Example: convert 15 MJ to J: 15 MJ = 15 × 1000000 J = 15000000 J
Formula
J = MJ × 1000000
Derivation from SI units:
- 1 MJ = 10⁶ J
- 1 J = 1 N·m = 1 W·s = 1 kg·m²·s⁻²
Both units are defined exactly, so the factor is exact. Megajoule definition: megajoule; Joule definition: joule.
Worked examples
- A reading of 35 MJ converts to 35000000 J.
35 MJ × 1000000 = 35000000 J - A value of 50 MJ is 50000000 J.
50 MJ × 1000000 = 50000000 J
Megajoule to Joule conversion table
| Megajoules (MJ) | Joules (J) |
|---|---|
| 1 MJ | 1000000 J |
| 3.6 MJ | 3600000 J |
| 10 MJ | 10000000 J |
| 35 MJ | 35000000 J |
| 38 MJ | 38000000 J |
| 45 MJ | 45000000 J |
| 50 MJ | 50000000 J |
| 100 MJ | 100000000 J |
| 1000 MJ | 1000000000 J |
Where it's used
Megajoules are used for fuel heating values (natural gas ≈ 38 MJ/m³, diesel ≈ 45 MJ/kg), while joules appear in physics and engineering energy balances. Both measure energy, work and heat, so the conversion is a fixed factor.
Megajoule to other energy units
| Conversion | 1 MJ equals |
|---|---|
| megajoule to joule | 1000000 J |
| megajoule to kilojoule | 1000 kJ |
| megajoule to calorie | 239005.7361 cal |
| megajoule to kilocalorie | 239.0057361 kcal |
| megajoule to watt-hour | 277.7777778 Wh |
| megajoule to kilowatt-hour | 0.2777777778 kWh |
| megajoule to BTU | 947.8171203 BTU |
| megajoule to therm | 0.00948043428 thm |
| megajoule to electronvolt | 6.241509074 × 10²⁴ eV |
| megajoule to foot-pound | 737562.1493 ft·lbf |
| megajoule to erg | 10000000000000 erg |
Frequently asked questions
How many joules are in 1 megajoule?
1 MJ = 1000000 J.
How do I convert megajoules to joules?
Multiply the value in MJ by 1000000. For example, 15 MJ × 1000000 = 15000000 J.
Is the MJ to J conversion exact?
Yes. Both units are defined exactly, and 1 MJ is exactly 1000000 J.
Sources
- The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Table 7, SI prefixes.
- The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Table 4, coherent derived units with special names.
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Convert Megajoules to Joules (MJ to J). Retrieved October 18, 2026, from https://scientificconverters.com/energy/megajoules-to-joules/
IEEE
Scientific Converters, "Convert Megajoules to Joules (MJ to J)," scientificconverters.com. Accessed: Oct. 18, 2026. [Online]. Available: https://scientificconverters.com/energy/megajoules-to-joules/