Foot-pound per Second (ft·lbf/s)
The foot-pound per second is the US mechanical power unit from which the horsepower (550 ft·lbf/s) is defined.
Symbol: ft·lbf/s (ASCII: ft-lbf/s)
Quantity: power (energy per unit time)
SI relation: 1 ft·lbf/s = 1.355817948331 W (exact)
Derivation: 1 ft·lbf/s = 1.3558179483314 W
Exact: yes, by definition
Typical uses
- Mechanics problems in US units
- Deriving horsepower from force and speed
Convert foot-pounds per second to other units
| Conversion | 1 ft·lbf/s equals | Reverse |
|---|---|---|
| foot-pound per second to watt | 1.355817948 W | watt to foot-pound per second |
| foot-pound per second to kilowatt | 0.001355817948 kW | kilowatt to foot-pound per second |
| foot-pound per second to horsepower | 0.001818181818 hp | horsepower to foot-pound per second |
| foot-pound per second to BTU per hour | 4.626242868 BTU/h | BTU per hour to foot-pound per second |
| foot-pound per second to refrigeration ton | 0.000385520239 TR | refrigeration ton to foot-pound per second |
| foot-pound per second to megawatt | 0.000001355817948 MW | megawatt to foot-pound per second |
| foot-pound per second to metric horsepower | 0.001843399392 PS | metric horsepower to foot-pound per second |
| foot-pound per second to milliwatt | 1355.817948 mW | milliwatt to foot-pound per second |
| foot-pound per second to kilocalorie per hour | 1.165793593 kcal/h | kilocalorie per hour to foot-pound per second |
Open the Power Converter to convert any value between all units.
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, "foot pound-force per second".
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). Foot-pound per Second (ft·lbf/s). Retrieved October 17, 2026, from https://scientificconverters.com/units/foot-pound-force-per-second/
IEEE
Scientific Converters, "Foot-pound per Second (ft·lbf/s)," scientificconverters.com. Accessed: Oct. 17, 2026. [Online]. Available: https://scientificconverters.com/units/foot-pound-force-per-second/