Convert Foot-Pounds per Second to BTU per Second
Convert Foot-Pounds per Second (ft⋅lbf/s) to BTU per Second (BTU/s) instantly and accurately.
Conversion Formula
BTU/s = ft⋅lbf/s × 0.001285067463
About Foot-Pounds per Second
One foot-pound per second (ft·lbf/s) ≈ 1.3558 W - the natural power unit in the foot-pound-second (FPS) system. Since 1 mechanical horsepower = exactly 550 ft·lbf/s, the conversion 1 ft·lbf/s = 1/550 hp is exact. Used in FPS structural and fluid dynamics: beam deflection power, pump and turbine output, and ballistic energy-transfer calculations. 19th-century American industry rated waterwheel output in ft·lbf/s before horsepower standardisation. 1 ft·lbf/s = 1.35582 W.
About BTU per Second
One BTU per second (BTU/s) ≈ 1,055 W - close to 1 kW but slightly larger. Used when heat rates are so high that per-hour or per-minute numbers become unwieldy. In fire protection engineering, large house fires peak at 500-2,000 BTU/s; industrial fires at millions of BTU/s. Blast characterisation for petrochemical safety and large industrial heat exchangers with duties of millions of BTU/h are conveniently expressed in BTU/s. Since 1 BTU/s ≈ 1.055 kW, conversion to SI is straightforward. 1 BTU/s = 1,055.056 W.
Quick Reference Table
| Foot-Pounds per Second (ft⋅lbf/s) | BTU per Second (BTU/s) |
|---|---|
| 1 ft⋅lbf/s | 0.00128507 BTU/s |
| 2 ft⋅lbf/s | 0.00257013 BTU/s |
| 5 ft⋅lbf/s | 0.00642534 BTU/s |
| 10 ft⋅lbf/s | 0.0128507 BTU/s |
| 25 ft⋅lbf/s | 0.0321267 BTU/s |
| 50 ft⋅lbf/s | 0.0642534 BTU/s |
| 100 ft⋅lbf/s | 0.128507 BTU/s |