Convert BTU to Megajoules
1 British thermal unit (BTU) equals 0.001055055853 megajoules (MJ).
1 BTU = 0.001055055853 MJ
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk BTU to megajoule converter to paste a column from Excel.
How to Convert BTU to Megajoule
- 1 BTU = 0.001055055853 MJ
- 1 MJ = 947.8171203 BTU
- Example: convert 15 BTU to MJ: 15 BTU = 15 × 0.001055055853 MJ = 0.01582583779 MJ
Reference conditions. BTU: International Table BTU (BTU_IT), 1055.05585262 J exactly.
Formula
MJ = BTU × 0.00105505585262
or MJ = BTU ÷ 947.8171203133
Derivation from SI units:
- 1 BTU_IT = 1055.05585262 J (exact)
- 1 MJ = 10⁶ J
- 1 BTU = 1055.05585262 J ÷ 1000000 J per MJ = 0.00105505585262 MJ
Both units are defined exactly, so the factor is exact. BTU definition: British thermal unit; Megajoule definition: megajoule.
Worked examples
- A reading of 3412 BTU converts to 3.599850569 MJ.
3412 BTU × 0.001055055853 = 3.599850569 MJ - A value of 24000 BTU is 25.32134046 MJ.
24000 BTU × 0.001055055853 = 25.32134046 MJ
BTU to Megajoule conversion table
| BTU | Megajoules (MJ) |
|---|---|
| 1 BTU | 0.001055055853 MJ |
| 100 BTU | 0.1055055853 MJ |
| 1000 BTU | 1.055055853 MJ |
| 3412 BTU | 3.599850569 MJ |
| 5000 BTU | 5.275279263 MJ |
| 10000 BTU | 10.55055853 MJ |
| 12000 BTU | 12.66067023 MJ |
| 24000 BTU | 25.32134046 MJ |
| 50000 BTU | 52.75279263 MJ |
| 100000 BTU | 105.5055853 MJ |
| 1000000 BTU | 1055.055853 MJ |
Where it's used
BTU are used for furnace, boiler and fuel ratings in the US, while megajoules appear in fuel heating values (natural gas ≈ 38 MJ/m³, diesel ≈ 45 MJ/kg). Both measure energy, work and heat, so the conversion is a fixed factor.
BTU to other energy units
| Conversion | 1 BTU equals |
|---|---|
| BTU to joule | 1055.055853 J |
| BTU to kilojoule | 1.055055853 kJ |
| BTU to megajoule | 0.001055055853 MJ |
| BTU to calorie | 252.1644007 cal |
| BTU to kilocalorie | 0.2521644007 kcal |
| BTU to watt-hour | 0.2930710702 Wh |
| BTU to kilowatt-hour | 0.0002930710702 kWh |
| BTU to therm | 0.00001000238767 thm |
| BTU to electronvolt | 6.585140678 × 10²¹ eV |
| BTU to foot-pound | 778.1692623 ft·lbf |
| BTU to erg | 10550558530 erg |
Frequently asked questions
How many megajoules are in 1 British thermal unit?
1 BTU = 0.001055055853 MJ.
How do I convert British thermal units to megajoules?
Multiply the value in BTU by 0.001055055853, or divide it by 947.8171203. For example, 15 BTU × 0.001055055853 = 0.01582583779 MJ.
Is the BTU to MJ conversion exact?
Yes. Both units are defined exactly, so the ratio is exact; its decimal form does not terminate and is shown here to 10 significant figures (more with the precision selector).
Sources
- Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology , Appendix B.8, "British thermal unit_IT (Btu_IT)".
- 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 BTU to Megajoules. Retrieved October 17, 2026, from https://scientificconverters.com/energy/btu-to-megajoules/
IEEE
Scientific Converters, "Convert BTU to Megajoules," scientificconverters.com. Accessed: Oct. 17, 2026. [Online]. Available: https://scientificconverters.com/energy/btu-to-megajoules/