Foot pounds to Joules converter
Convert foot pounds (ft·lbf) to Joules (J). Calculate a value, check the formula and compare common measurements.
Result for the values shown.
Calculations run in your browser.
What to enter
| Input | Meaning and units |
|---|---|
| Value | Enter value using the definition in the method and example. |
| From | Select the unit or currency in which the entered number is currently expressed. |
| To | Select the unit or currency you need for the answer. |
Understanding your result
The converted value describes the same energy quantity in the selected target unit. Display rounding does not add precision to the original measurement.
Common mistakes
- Confusing the source and target units, or overlooking a prefix or case-sensitive symbol.
Check your calculation
- Convert to the target unit and then reverse the direction. Within display rounding, you should recover the original value.
Read the energy measurement guide · Calculation checks, sources and review limits
How do I convert foot pounds to joules?
Enter the value in foot pounds to find the same energy quantity in joules. The number changes to match the unit; the underlying quantity stays the same. Check the definitions below when a unit has more than one convention.
Common uses
- Compare energy amounts stated in different units.
- Translate energy measurements on a specification or meter.
How it works
For the displayed direction, 1 ft·lbf equals 1.35581794833 J. The engine converts through the shared energy base quantity. Calories are thermochemical. BTU uses the international-table definition. Foot-pounds mean foot-pounds force. The multiplier is derived from the two centralized unit factors. Keep full precision until the final result; displayed answers use up to 12 significant digits.
Worked example
10 ft·lbf converts to 13.5581794833 J. For the reverse direction, swap the units and enter 13.5581794833 J; the result is approximately 10 ft·lbf.
FAQ
How do I convert ft·lbf to J?
J = ft·lbf × 1.35581794833
Which definition is used?
Calories are thermochemical. BTU uses the international-table definition. Foot-pounds mean foot-pounds force.
Common values
Use “Swap units” above for the reverse conversion. Values below are rounded to six significant digits.
| foot pounds | Joules |
|---|---|
| 1 | 1.35582 |
| 5 | 6.77909 |
| 10 | 13.5582 |
| 20 | 27.1164 |
| 30 | 40.6745 |
| 50 | 67.7909 |
| 100 | 135.582 |