Foot Pounds to Joules
A foot-pound is the energy of one pound of force acting over one foot, used to describe bolt torque and impact energy in the US. The joule is the SI unit of energy, defined as the work done by one newton over one meter. 1 ft·lbf equals ≈1.35582 J, so converting between them is a matter of multiplying by that fixed factor — type any value into the converter below and both sides update instantly as you type.
Both units belong to energy, measured here against energy's base unit (J) — every other energy unit on this site converts through that same reference point, which is why the table below can also be read as a quick cross-check against nearby values.
Formula
J = ft·lbf × ≈1.35582
ft·lbf = J × ≈0.737562
Worked example: 5 ft·lbf × ≈1.35582 = ≈6.77909 J.
Conversion table
| Foot-pound (ft·lbf) | Joule (J) |
|---|---|
| 1 ft·lbf | ≈1.35582 J |
| 2 ft·lbf | ≈2.71164 J |
| 3 ft·lbf | ≈4.06745 J |
| 5 ft·lbf | ≈6.77909 J |
| 10 ft·lbf | ≈13.5582 J |
| 20 ft·lbf | ≈27.1164 J |
| 25 ft·lbf | ≈33.8954 J |
| 50 ft·lbf | ≈67.7909 J |
| 100 ft·lbf | ≈135.582 J |
| 250 ft·lbf | ≈338.954 J |
| 500 ft·lbf | ≈677.909 J |
| 1,000 ft·lbf | ≈1,355.82 J |
Frequently asked
- How many Joules in a foot-pound?
- 1 ft·lbf equals ≈1.35582 J.
- How do I convert Foot-pounds to Joules?
- Multiply the value in ft·lbf by ≈1.35582 to get J. The converter above does this instantly as you type.
- Is the conversion exact?
- Yes — Foot-pound and Joule are both defined by a fixed conversion factor to energy's base unit (J), so the result shown is exact to the precision displayed, not an approximation.