Convert Kilojoules to BTU
1 kilojoule (kJ) equals 0.9478171203 British thermal units (BTU).
1 kJ = 0.9478171203 BTU
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk kilojoule to BTU converter to paste a column from Excel.
How to Convert Kilojoule to BTU
- 1 kJ = 0.9478171203 BTU
- 1 BTU = 1.055055853 kJ
- Example: convert 15 kJ to BTU: 15 kJ = 15 × 0.9478171203 BTU = 14.2172568 BTU
Reference conditions. BTU: International Table BTU (BTU_IT), 1055.05585262 J exactly.
Formula
BTU = kJ × 0.9478171203133
or BTU = kJ ÷ 1.05505585262
Derivation from SI units:
- 1 kJ = 10³ J
- 1 BTU_IT = 1055.05585262 J (exact)
- 1 kJ = 1000 J ÷ 1055.05585262 J per BTU = 0.9478171203133 BTU
Both units are defined exactly, so the factor is exact. Kilojoule definition: kilojoule; BTU definition: British thermal unit.
Worked examples
- A reading of 100 kJ converts to 94.78171203 BTU.
100 kJ × 0.9478171203 = 94.78171203 BTU - A value of 1000 kJ is 947.8171203 BTU.
1000 kJ × 0.9478171203 = 947.8171203 BTU
Kilojoule to BTU conversion table
| Kilojoules (kJ) | BTU |
|---|---|
| 1 kJ | 0.9478171203 BTU |
| 4.184 kJ | 3.965666831 BTU |
| 10 kJ | 9.478171203 BTU |
| 50 kJ | 47.39085602 BTU |
| 100 kJ | 94.78171203 BTU |
| 250 kJ | 236.9542801 BTU |
| 500 kJ | 473.9085602 BTU |
| 840 kJ | 796.1663811 BTU |
| 1000 kJ | 947.8171203 BTU |
| 2000 kJ | 1895.634241 BTU |
| 8700 kJ | 8246.008947 BTU |
| 10000 kJ | 9478.171203 BTU |
Where it's used
Kilojoules are used for nutrition labels (kJ per serving), while British thermal units appear in furnace, boiler and fuel ratings in the US. Both measure energy, work and heat, so the conversion is a fixed factor.
Kilojoule to other energy units
| Conversion | 1 kJ equals |
|---|---|
| kilojoule to joule | 1000 J |
| kilojoule to megajoule | 0.001 MJ |
| kilojoule to calorie | 239.0057361 cal |
| kilojoule to kilocalorie | 0.2390057361 kcal |
| kilojoule to watt-hour | 0.2777777778 Wh |
| kilojoule to kilowatt-hour | 0.0002777777778 kWh |
| kilojoule to BTU | 0.9478171203 BTU |
| kilojoule to therm | 0.00000948043428 thm |
| kilojoule to electronvolt | 6.241509074 × 10²¹ eV |
| kilojoule to foot-pound | 737.5621493 ft·lbf |
| kilojoule to erg | 10000000000 erg |
Frequently asked questions
How many British thermal units are in 1 kilojoule?
1 kJ = 0.9478171203 BTU.
How do I convert kilojoules to British thermal units?
Multiply the value in kJ by 0.9478171203, or divide it by 1.055055853. For example, 15 kJ × 0.9478171203 = 14.2172568 BTU.
Is the kJ to BTU 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
- The International System of Units (SI), 9th edition (SI Brochure), Bureau International des Poids et Mesures , Table 7, SI prefixes.
- 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)".
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 Kilojoules to BTU. Retrieved October 17, 2026, from https://scientificconverters.com/energy/kilojoules-to-btu/
IEEE
Scientific Converters, "Convert Kilojoules to BTU," scientificconverters.com. Accessed: Oct. 17, 2026. [Online]. Available: https://scientificconverters.com/energy/kilojoules-to-btu/