Convert Foot-Pound-Force to Millijoules

Convert Foot-Pound-Force (ft·lbf) to Millijoules (mJ) instantly and accurately.

Conversion Formula

mJ = ft·lbf × 1355.817948

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.

About Millijoules

A millijoule (mJ) is 10⁻³ J - the scale of surgical lasers, spark ignition, and the kinetic energy of small everyday objects. Nd:YAG lasers for ophthalmology and tattoo removal deliver 10-200 mJ per pulse. The minimum spark energy to ignite methane-air is ~0.29 mJ; an automotive spark plug discharges 30-60 mJ per cycle. A 2 g mosquito flying at 1 m/s has kinetic energy ½ × 0.002 × 1² = 1 mJ. Electrocautery monopolar pulses deliver 50-500 mJ to coagulate blood vessels. 1 mJ = 10⁻³ J = 0.2390 cal.

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