Convert BTU to Kilocalories
1 British thermal unit (BTU) equals 0.2521644007 kilocalories (kcal).
1 BTU = 0.2521644007 kcal
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk BTU to kilocalorie converter to paste a column from Excel.
How to Convert BTU to Kilocalorie
- 1 BTU = 0.2521644007 kcal
- 1 kcal = 3.965666831 BTU
- Example: convert 15 BTU to kcal: 15 BTU = 15 × 0.2521644007 kcal = 3.782466011 kcal
Reference conditions. BTU: International Table BTU (BTU_IT), 1055.05585262 J exactly. kcal: Thermochemical kilocalorie (food Calorie), 4184 J exactly.
Formula
kcal = BTU × 0.2521644007218
or kcal = BTU ÷ 3.965666831391
Derivation from SI units:
- 1 BTU_IT = 1055.05585262 J (exact)
- 1 kcal = 1000 cal = 4184 J (exact)
- 1 BTU = 1055.05585262 J ÷ 4184 J per kcal = 0.2521644007218 kcal
Both units are defined exactly, so the factor is exact. BTU definition: British thermal unit; Kilocalorie definition: kilocalorie.
Worked examples
- A reading of 3412 BTU converts to 860.3849353 kcal.
3412 BTU × 0.2521644007 = 860.3849353 kcal - A value of 24000 BTU is 6051.945617 kcal.
24000 BTU × 0.2521644007 = 6051.945617 kcal
BTU to Kilocalorie conversion table
| BTU | Kilocalories (kcal) |
|---|---|
| 1 BTU | 0.2521644007 kcal |
| 100 BTU | 25.21644007 kcal |
| 1000 BTU | 252.1644007 kcal |
| 3412 BTU | 860.3849353 kcal |
| 5000 BTU | 1260.822004 kcal |
| 10000 BTU | 2521.644007 kcal |
| 12000 BTU | 3025.972809 kcal |
| 24000 BTU | 6051.945617 kcal |
| 50000 BTU | 12608.22004 kcal |
| 100000 BTU | 25216.44007 kcal |
| 1000000 BTU | 252164.4007 kcal |
Where it's used
BTU are used for furnace, boiler and fuel ratings in the US, while kilocalories appear in food and diet energy (2000 kcal reference intake). 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 kilocalories are in 1 British thermal unit?
1 BTU = 0.2521644007 kcal.
How do I convert British thermal units to kilocalories?
Multiply the value in BTU by 0.2521644007, or divide it by 3.965666831. For example, 15 BTU × 0.2521644007 = 3.782466011 kcal.
Is the BTU to kcal 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)".
- 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, "kilocalorie (thermochemical)".
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 Kilocalories. Retrieved October 17, 2026, from https://scientificconverters.com/energy/btu-to-kilocalories/
IEEE
Scientific Converters, "Convert BTU to Kilocalories," scientificconverters.com. Accessed: Oct. 17, 2026. [Online]. Available: https://scientificconverters.com/energy/btu-to-kilocalories/