Convert British Thermal Units to Foot-Pound-Force
Convert British Thermal Units (BTU) to Foot-Pound-Force (ft·lbf) instantly and accurately.
Conversion Formula
ft·lbf = BTU × 778.1692623
About British Thermal Units
A British Thermal Unit (BTU) - the heat to raise 1 lb of water by 1°F - equals exactly 1,055.05585262 J. It dominates US HVAC: room air conditioners are rated in BTU/h (5,000-24,000 BTU/h = 1.5-7.0 kW); one ton of refrigeration is exactly 12,000 BTU/h. Natural gas is billed in therms (100,000 BTU) in the US. Higher heating values: natural gas ~1,020-1,050 BTU/ft³; No. 2 fuel oil ~138,700 BTU/US gal; propane ~91,500 BTU/US gal. 1 BTU = 1,055.06 J = 252.164 cal = 0.29307 Wh.
About Foot-Pound-Force
A foot-pound-force (ft·lbf) is the work done by one pound-force through one foot - exactly 1.3558179483314004 J. It is the standard torque and energy unit in US engineering. Automotive engine torque: Honda Civic ~125 lb-ft; Ford F-150 EcoBoost ~500 lb-ft. Muzzle energies: .22 LR ~140 ft·lbf; .308 Winchester ~2,600 ft·lbf; .50 BMG ~14,000 ft·lbf. Diesel pile hammers deliver 15,000-600,000 ft·lbf/blow. SAE Grade 8 bolts are specified at 7-950 ft·lbf. 1 ft·lbf = 12 in·lbf = 1.35582 J = 0.32405 cal.
Quick Reference Table
| British Thermal Units (BTU) | Foot-Pound-Force (ft·lbf) |
|---|---|
| 1 BTU | 778.169 ft·lbf |
| 2 BTU | 1556.34 ft·lbf |
| 5 BTU | 3890.85 ft·lbf |
| 10 BTU | 7781.69 ft·lbf |
| 25 BTU | 19454.2 ft·lbf |
| 50 BTU | 38908.5 ft·lbf |
| 100 BTU | 77816.9 ft·lbf |