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Energy
Foot-pounds to Kilojoules
Convert foot-pounds (ft·lb) to kilojoules (kJ). Type a value below to see the result update instantly. Reference table and formula included.
Calculator
1 ft·lb = 0.001356 kJ
Foot-pounds to Kilojoules Conversion Table
Common values, ready to copy:
| foot-pounds | kilojoules |
|---|---|
| 1 ft·lb | 0.001356 kJ |
| 2 ft·lb | 0.002712 kJ |
| 5 ft·lb | 0.006779 kJ |
| 10 ft·lb | 0.013558 kJ |
| 25 ft·lb | 0.033895 kJ |
| 50 ft·lb | 0.067791 kJ |
| 100 ft·lb | 0.135582 kJ |
| 1,000 ft·lb | 1.3558 kJ |
Formula
kilojoules = foot-pounds × 0.00135582
Energy uses the SI joule. Food calories (kcal) are 1,000 small calories: 1 kcal = 4,184 J. 1 kWh = 3.6 MJ = 3,600,000 J. 1 BTU = 1,055.06 J.
About Foot-pounds and Kilojoules
Foot-pounds (ft·lb): The work done lifting one pound through one foot against gravity; 1 ft·lb = 1.35582 J. Common uses: Torque specifications in US automotive contexts (lug nuts, bolt torque), and some US engineering work.
Kilojoules (kJ): A thousand joules; the practical SI energy unit for food and nutrition in metric countries. Common uses: Food energy labeling outside the US, electrical energy in kJ for small batteries, and biology (metabolism).
How the conversion works
Energy uses the SI joule. Food calories (kcal) are 1,000 small calories: 1 kcal = 4,184 J. 1 kWh = 3.6 MJ = 3,600,000 J. 1 BTU = 1,055.06 J.
The exact relationship is kilojoules = foot-pounds × 0.00135582, which the calculator at the top of this page applies in both directions. Type into either field and the other updates immediately.
When this conversion matters
Converting between foot-pounds and kilojoules comes up wherever energy measurements move between systems — from one country's conventions to another's, from a scientific reference to a practical specification, or from one industry's working unit to another's. The calculator and reference table above cover the everyday range; for unusual values you can type any number into either field.