Convert Megajoules to Kilojoules
1 megajoule (MJ) equals 1000 kilojoules (kJ).
1 MJ = 1000 kJ
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk megajoule to kilojoule converter to paste a column from Excel.
How to Convert Megajoule to Kilojoule
- 1 MJ = 1000 kJ
- 1 kJ = 0.001 MJ
- Example: convert 15 MJ to kJ: 15 MJ = 15 × 1000 kJ = 15000 kJ
Formula
kJ = MJ × 1000
Derivation from SI units:
- 1 MJ = 10⁶ J
- 1 kJ = 10³ J
- 1 MJ = 1000000 J ÷ 1000 J per kJ = 1000 kJ
Both units are defined exactly, so the factor is exact. Megajoule definition: megajoule; Kilojoule definition: kilojoule.
Worked examples
- A reading of 35 MJ converts to 35000 kJ.
35 MJ × 1000 = 35000 kJ - A value of 50 MJ is 50000 kJ.
50 MJ × 1000 = 50000 kJ
Megajoule to Kilojoule conversion table
| Megajoules (MJ) | Kilojoules (kJ) |
|---|---|
| 1 MJ | 1000 kJ |
| 3.6 MJ | 3600 kJ |
| 10 MJ | 10000 kJ |
| 35 MJ | 35000 kJ |
| 38 MJ | 38000 kJ |
| 45 MJ | 45000 kJ |
| 50 MJ | 50000 kJ |
| 100 MJ | 100000 kJ |
| 1000 MJ | 1000000 kJ |
Where it's used
Megajoules are used for fuel heating values (natural gas ≈ 38 MJ/m³, diesel ≈ 45 MJ/kg), while kilojoules appear in nutrition labels (kJ per serving). 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 kilojoules are in 1 megajoule?
1 MJ = 1000 kJ.
How do I convert megajoules to kilojoules?
Multiply the value in MJ by 1000. For example, 15 MJ × 1000 = 15000 kJ.
Is the MJ to kJ conversion exact?
Yes. Both units are defined exactly, and 1 MJ is exactly 1000 kJ.
Sources
- The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Table 7, SI prefixes.
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 Kilojoules. Retrieved October 17, 2026, from https://scientificconverters.com/energy/megajoules-to-kilojoules/
IEEE
Scientific Converters, "Convert Megajoules to Kilojoules," scientificconverters.com. Accessed: Oct. 17, 2026. [Online]. Available: https://scientificconverters.com/energy/megajoules-to-kilojoules/