How many kilojoules is 1 foot-pound?

1 foot-pound-force (ft·lbf) equals 0.00135582 kilojoules (kJ). This is because 1 ft·lbf = 1.35582 joules, and 1 kJ = 1000 J, so 1.35582 / 1000 = 0.00135582 kJ.

How do I convert foot-pounds to kilojoules manually?

Multiply the foot-pound value by 0.00135582. For example, 1000 ft·lbf × 0.00135582 = 1.35582 kJ. To convert kilojoules back to foot-pounds, multiply by 737.562 (or divide by 0.00135582).

What is a foot-pound (ft·lbf)?

A foot-pound-force (ft·lbf) is an imperial unit of energy or work. It represents the work done when a force of one pound-force moves an object one foot in the direction of the force. It is commonly used in mechanical engineering, ballistics, and automotive contexts in the US.

What is a kilojoule (kJ)?

A kilojoule is an SI (metric) unit of energy equal to 1000 joules. Kilojoules are widely used in engineering, physics, nutrition (food energy), and thermodynamics internationally, making them the standard for energy reporting outside the US.

When would I need to convert ft·lbf to kJ?

This conversion is common when working with international engineering standards, comparing ballistic energy across regions, or reporting mechanical work in SI units. It also appears in materials science (Charpy impact testing often reports in J or kJ) and automotive engineering.

Is foot-pound the same as pound-foot?

No. Foot-pound (ft·lbf) is a unit of energy or work. Pound-foot (lb·ft) is a unit of torque. Although they appear numerically equivalent in some contexts, they represent different physical quantities. This converter deals with ft·lbf (energy), not lb·ft (torque).

Foot Pounds to Kilojoules Converter

Name: Foot Pounds to Kilojoules Converter
Availability: InStock
Author: Nham Vu

Enter a value in foot-pounds and get the kilojoule equivalent instantly, with reverse kilojoule-to-foot-pound conversion and a reference table.

Converter

Energy in Foot-Pounds (ft·lbf)

= 1.35582 kJ

Energy in Kilojoules (kJ)

= 737.562 ft·lbf

Reference Table

ft·lbf	kJ
1	0.00135582
10	0.0135582
100	0.135582
500	0.67791
737.562	1
1,000	1.35582
5,000	6.7791
10,000	13.5582
50,000	67.791
100,000	135.582

1 ft·lbf = 1.35582 J = 0.00135582 kJ. Conversion factor: 1 ft·lbf = 0.3048 m × 4.44822 N = 1.35582 J.

Summary

Enter a value in foot-pounds and get the kilojoule equivalent instantly, with reverse kilojoule-to-foot-pound conversion and a reference table.

How it works

Enter an energy value in foot-pounds in the top input field.
The kilojoule result appears instantly — no button press needed.
Use the reverse field to convert kilojoules back to foot-pounds.
Click "Copy" next to any result to copy the value to your clipboard.
Check the reference table for common ft·lbf-to-kJ values at a glance.

Use cases

Convert mechanical work in foot-pounds to kilojoules for SI-unit engineering reports.
Translate firearm or ballistic muzzle energy from ft·lbf to kJ for international specs.
Compare engine torque output in foot-pounds against kilojoule energy budgets.
Convert impact energy ratings from ft·lbf to kJ in materials testing and Charpy tests.
Cross-check spring or tension energy stored in foot-pounds with SI kilojoule targets.
Verify thermodynamic cycle work values when mixing imperial and metric energy units.
Convert mechanical power calculations from ft·lbf per revolution to kilojoule equivalents.
Translate structural load-displacement work results from ft·lbf to kJ for standards compliance.

Frequently Asked Questions

Last updated: 2026-07-23 · Reviewed by Nham Vu