Convert Foot-Pound-Force to Kilojoules

Convert Foot-Pound-Force (ft·lbf) to Kilojoules (kJ) instantly and accurately.

Foot-Pound-Force (ft·lbf)
Kilojoules (kJ)

Conversion Formula

kJ = ft·lbf × 0.001355817948

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 Kilojoules

A kilojoule (kJ) is exactly 1,000 J and is the standard energy unit for food and physical chemistry. EU, Australian, and NZ food labels are mandatory in kJ: recommended adult intake is ~8,400 kJ/day. Bond dissociation energies: C-H bond 413 kJ/mol; C=C double bond 614 kJ/mol; N≡N triple bond 945 kJ/mol. Specific heat of water: 4.184 kJ/(kg·K). A cyclist riding at 150 W for one hour expends 540 kJ. Charpy and Izod impact toughness tests record results in J and kJ. 1 kJ = 1,000 J = 239.0 cal = 0.94782 BTU = 0.27778 Wh.

Quick Reference Table

Foot-Pound-Force (ft·lbf)Kilojoules (kJ)
1 ft·lbf0.00135582 kJ
2 ft·lbf0.00271164 kJ
5 ft·lbf0.00677909 kJ
10 ft·lbf0.0135582 kJ
25 ft·lbf0.0338954 kJ
50 ft·lbf0.0677909 kJ
100 ft·lbf0.135582 kJ

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