Convert Horsepower to Kilocalories per Hour
1 horsepower (hp) equals 641.186476 kilocalories per hour (kcal/h).
1 hp = 641.186476 kcal/h
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk horsepower to kilocalorie per hour converter to paste a column from Excel.
How to Convert Horsepower to Kilocalorie per Hour
- 1 hp = 641.186476 kcal/h
- 1 kcal/h = 0.00155960869 hp
- Example: convert 15 hp to kcal/h: 15 hp = 15 × 641.186476 kcal/h = 9617.79714 kcal/h
Reference conditions. hp: Mechanical (imperial) horsepower, 550 ft·lbf/s. Metric horsepower (PS) is about 1.4 % smaller. kcal/h: Uses the International Table kilocalorie (4186.8 J), the convention in heating and HVAC: 1 kcal/h = 1.163 W.
Formula
kcal/h = hp × 641.1864759951
Derivation from SI units:
- 1 hp = 550 ft·lbf/s = 745.69987158227 W
- 1 kcal_IT/h = 4186.8 J ÷ 3600 s = 1.163 W (exact)
- 1 hp = 745.6998715823 W ÷ 1.163 W per kcal/h = 641.1864759951 kcal/h
Both units are defined exactly, so the factor is exact. Horsepower definition: horsepower; Kilocalorie per Hour definition: kilocalorie per hour.
Worked examples
- A reading of 5 hp converts to 3205.93238 kcal/h.
5 hp × 641.186476 = 3205.93238 kcal/h - A value of 150 hp is 96177.9714 kcal/h.
150 hp × 641.186476 = 96177.9714 kcal/h
Horsepower to Kilocalorie per Hour conversion table
| Horsepower (hp) | Kilocalories per Hour (kcal/h) |
|---|---|
| 0.25 hp | 160.296619 kcal/h |
| 0.5 hp | 320.593238 kcal/h |
| 1 hp | 641.186476 kcal/h |
| 1.5 hp | 961.779714 kcal/h |
| 2 hp | 1282.372952 kcal/h |
| 5 hp | 3205.93238 kcal/h |
| 10 hp | 6411.86476 kcal/h |
| 25 hp | 16029.6619 kcal/h |
| 50 hp | 32059.3238 kcal/h |
| 100 hp | 64118.6476 kcal/h |
| 150 hp | 96177.9714 kcal/h |
| 200 hp | 128237.2952 kcal/h |
| 300 hp | 192355.9428 kcal/h |
| 400 hp | 256474.5904 kcal/h |
| 500 hp | 320593.238 kcal/h |
| 1000 hp | 641186.476 kcal/h |
Where it's used
Horsepower are used for car and motorcycle engine power in the US and UK, while kilocalories per hour appear in radiator and boiler ratings in older European data. Both measure power (energy per unit time), so the conversion is a fixed factor.
Horsepower to other power units
| Conversion | 1 hp equals |
|---|---|
| horsepower to watt | 745.6998716 W |
| horsepower to milliwatt | 745699.8716 mW |
| horsepower to kilowatt | 0.7456998716 kW |
| horsepower to megawatt | 0.0007456998716 MW |
| horsepower to metric horsepower | 1.013869665 PS |
| horsepower to BTU per hour | 2544.433578 BTU/h |
| horsepower to refrigeration ton | 0.2120361315 TR |
| horsepower to kilocalorie per hour | 641.186476 kcal/h |
| horsepower to foot-pound per second | 550 ft·lbf/s |
Frequently asked questions
How many kilocalories per hour are in 1 horsepower?
1 hp = 641.186476 kcal/h.
How do I convert horsepower to kilocalories per hour?
Multiply the value in hp by 641.186476. For example, 15 hp × 641.186476 = 9617.79714 kcal/h.
Is the hp to kcal/h 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, "horsepower (550 ft·lbf/s)".
- 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, "calorie_IT" with hour.
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 Horsepower to Kilocalories per Hour. Retrieved October 17, 2026, from https://scientificconverters.com/power/horsepower-to-kilocalories-per-hour/
IEEE
Scientific Converters, "Convert Horsepower to Kilocalories per Hour," scientificconverters.com. Accessed: Oct. 17, 2026. [Online]. Available: https://scientificconverters.com/power/horsepower-to-kilocalories-per-hour/