Kilojoules (kJ) to Foot-Pounds-Force (ft·lbf) Converter
Enter a value to instantly convert between energy units.
1 Kilojoule = 737.5621 Foot-Pound Force
Key Formulas
Kilocalorie → Kilojoule
kJ = kcal × 4.184Kilojoule → Kilocalorie
kcal = kJ × 0.239006Kilowatt-Hour → Joule
J = kWh × 3600000Joule → Kilowatt-Hour
kWh = J × 2.77778e-7Formula
ft·lbf = kJ × 737.5621Foot-pounds-force (ft·lbf) is the imperial unit of energy, expressing work done by lifting a 1-pound weight by 1 foot. Kilojoules are the metric standard. You need this conversion when designing machinery in countries that use imperial units, reading HVAC system specifications (cooling capacity in ft·lbf-per-second), or comparing mechanical power across US and metric documentation. The factor (~738) comes from the conversion between SI and imperial force/distance definitions.
Source: NIST SP 811, Table B.8
Frequently Asked Questions
Real-World Examples
An engineer designing an air-conditioning unit with a cooling capacity of 1 kJ/second (1 kilowatt). In imperial specs, this is ~738 ft·lbf/second of mechanical work.
1 kJ = 737.56 ft·lbf
A pump manufacturer converting 10 kJ of energy per stroke into US sales specs: ~7,400 ft·lbf, helping customers understand power in familiar terms.
10 kJ = 7375.6 ft·lbf
A hydraulic system designer specifying 500 joules (0.5 kJ) pressure-relief valve capacity, documented as ~369 ft·lbf in equipment manuals for US contractors.
0.5 kJ = 368.78 ft·lbf
A mechanical technician troubleshooting a motor rated at 2 kJ per revolution; parts list shows ~1,475 ft·lbf for comparing to available replacement motors.
2 kJ = 1475.12 ft·lbf