Foot-pounds to Kilojoules Converter
Enter the energy in foot-pounds below to convert it to kilojoules.
Convert Foot-pounds to Kilojoules
Enter a value in foot-pounds (ft·lbf) to convert to kilojoules (kJ).
Foot-pound to Kilojoule Conversion Table
Table showing various foot-pound measurements converted to kilojoules. Click any preset value or arrow to load it into the converter.
| Foot-pounds (ft·lbf) | Kilojoules (kJ) |
|---|---|
| 1 ft·lbf | 0.0013558 kJ |
| 2 ft·lbf | 0.0027116 kJ |
| 2.5 ft·lbf | 0.0033895 kJ |
| 5 ft·lbf | 0.0067791 kJ |
| 10 ft·lbf | 0.0135582 kJ |
| 15 ft·lbf | 0.0203373 kJ |
| 20 ft·lbf | 0.0271164 kJ |
| 25 ft·lbf | 0.0338954 kJ |
| 30 ft·lbf | 0.0406745 kJ |
| 50 ft·lbf | 0.0677909 kJ |
How to Convert Foot-pounds to Kilojoules
To convert foot-pounds to kilojoules, multiply the energy by the following conversion ratio: 0.0013558 kilojoules/foot-pound.
Since one foot-pound is equal to 0.0013558 kilojoules, you can use this simple formula to convert:
The energy in kilojoules is equal to the energy in foot-pounds multiplied by 0.0013558.
For example, here's how to convert 5 foot-pounds to kilojoules using the formula above.
How Many Kilojoules Are in a Foot-pound?
There are 0.0013558 kilojoules in a foot-pound, which is why we use this value in the formula above.
Our foot-pound to kilojoule calculator automatically converts your energy measurements with full decimal and scientific precision across US customary, imperial, and SI metric standards.
Foot-pounds and kilojoules are both units used to measure energy. Keep reading to learn more about each unit.
What Is a Foot-pound?
A foot-pound is a unit of energy equal to 1.3558179 joules (J), the base unit for energy. Mechanical work unit equal to 1.355818 Joules. [1]
The foot-pound is classified as a US customary and imperial unit of energy. Foot-pounds can be abbreviated as ft·lbf; for example, 1 foot-pound can be written as 1 ft·lbf.
When working with foot-pounds (ft·lbf) in formulas or technical specifications, always verify whether your target system uses SI metric, US customary, or British imperial standards.
In practice, foot-pounds (ft·lbf) are widely used across standard energy applications within US customary and imperial workflows, engineering documentation, and technical data sheets.
What Is a Kilojoule?
A kilojoule is a unit of energy equal to 1,000 joules (J), the base unit for energy. Equal to 1,000 Joules. [2]
The kilojoule is classified as a metric and SI-compatible unit of energy. Kilojoules can be abbreviated as kJ; for example, 1 kilojoule can be written as 1 kJ.
In the metric system, "kilo" is the standard SI prefix for thousands, or 10³. This makes the kilojoule (kJ) a convenient decimal multiple of the joule (J).
In practice, kilojoules (kJ) are widely used across large-scale industrial, bulk, and macro-level energy specifications within SI metric workflows, engineering documentation, and technical data sheets.
When converting energy between foot-pounds (ft·lbf) and kilojoules (kJ), keep full floating-point precision (1 ft·lbf = 0.0013558 kJ; 1 kJ = 737.5621493 ft·lbf) during intermediate calculations and round only the final kilojoule figure to match your instrument tolerance.
More Foot-pound & Kilojoule Conversions
Need to calculate in the opposite direction? Use our kilojoules to foot-pounds calculator to switch your starting unit immediately. You can also explore related tools such as converting kilojoules to foot-pounds, converting joules to kilojoules, or converting kilocalories to kilojoules.
Convert from Foot-pounds
Frequently Asked Questions
References
- [1]NIST CODATA StandardNIST CODATA (CODATA Energy & Thermodynamic Constants)·Energy Metrology Standard — Foot-pounds (ft·lbf) to Kilojoules (kJ)
- [2]NIST SP 811 SpecificationNIST SP 811 (NIST SP 811 App. B.9 (Energy, Work & Heat))·Unit Specifications: Foot-pound (ft·lbf) (ft·lbf) & Kilojoule (kJ)
- [3]BIPM ReferenceBIPM (Derived SI Unit: Joule (J))·Conversion Factors & Mathematical Basis (ft·lbf to kJ)