1 ft·lbf = 1.35582 J (foot-pound (energy) → joule)
1 ft·lbf = 1.35582 J
1 foot-pound (energy) equals 1.35582 joules. To convert foot-pounds (energy) to joules, multiply the foot-pound (energy) value by 1.35582. For quick reference: 1 ft·lbf = 1.35582 J, 5 ft·lbf = 6.77909 J, 10 ft·lbf = 13.5582 J, 100 ft·lbf = 135.582 J.
Joules = Foot-pounds (energy) × 1.35582Start with your value in foot-pounds (energy).
Multiply the foot-pound (energy) value by 1.35582. This is the exact conversion factor from foot-pounds (energy) to joules.
The product is your value in joules. For example, 5 ft·lbf × 1.35582 = 6.77909 J.
The exact factor from foot-pounds (energy) to joules is 1.35582.
Joules = Foot-pounds (energy) × 1.35582
Fifty common reference values, hand-picked for skim utility. Use the calculator above for any value not listed.
| Foot-pounds (energy) (ft·lbf) | Joules (J) |
|---|---|
| 0.001 ft·lbf | 0.0013558 J |
| 0.01 ft·lbf | 0.013558 J |
| 0.1 ft·lbf | 0.13558 J |
| 0.5 ft·lbf | 0.67791 J |
| 1 ft·lbf | 1.3558 J |
| 1.5 ft·lbf | 2.0337 J |
| 2 ft·lbf | 2.7116 J |
| 5 ft·lbf | 6.7791 J |
| 10 ft·lbf | 13.558 J |
| 20 ft·lbf | 27.116 J |
| 50 ft·lbf | 67.791 J |
| 100 ft·lbf | 135.58 J |
| 200 ft·lbf | 271.16 J |
| 250 ft·lbf | 338.95 J |
| 500 ft·lbf | 677.91 J |
| 1000 ft·lbf | 1355.8 J |
| 2000 ft·lbf | 2711.6 J |
| 2500 ft·lbf | 3389.5 J |
| 3600 ft·lbf | 4880.9 J |
| 5000 ft·lbf | 6779.1 J |
| 7500 ft·lbf | 10169 J |
| 10000 ft·lbf | 13558 J |
| 25000 ft·lbf | 33895 J |
| 50000 ft·lbf | 67791 J |
| 100000 ft·lbf | 135582 J |
| 250000 ft·lbf | 338954 J |
| 500000 ft·lbf | 677909 J |
| 1000000 ft·lbf | 1355818 J |
| 2000000 ft·lbf | 2711636 J |
| 3600000 ft·lbf | 4880945 J |
| 5000000 ft·lbf | 6779090 J |
| 10000000 ft·lbf | 13558179 J |
| 25000000 ft·lbf | 33895449 J |
| 50000000 ft·lbf | 67790897 J |
| 100000000 ft·lbf | 135581795 J |
| 250000000 ft·lbf | 338954487 J |
| 500000000 ft·lbf | 677908974 J |
| 1000000000 ft·lbf | 1355817948 J |
| 2000000000 ft·lbf | 2711635897 J |
| 5000000000 ft·lbf | 6779089742 J |
| 10000000000 ft·lbf | 13558179483 J |
| 20000000000 ft·lbf | 27116358967 J |
| 50000000000 ft·lbf | 67790897417 J |
| 100000000000 ft·lbf | 135581794833 J |
| 1000000000000 ft·lbf | 1355817948331 J |
| 10000000000000 ft·lbf | 13558179483314 J |
| 100000000000000 ft·lbf | 135581794833140 J |
| 1000000000000000 ft·lbf | 1.3558 × 10^15 J |
| 10000000000000000 ft·lbf | 1.3558 × 10^16 J |
| 100000000000000000 ft·lbf | 1.3558 × 10^17 J |
A bow might deliver 60–80 ft·lb of kinetic energy to an arrow. A sledgehammer swing can deliver over 100 ft·lb of energy. In joules, that gives you: 1 ft·lbf = 1.35582 J, 10 ft·lbf = 13.5582 J, 100 ft·lbf = 135.582 J.
The foot-pound (ft·lbf) is the customary US/imperial unit of energy and work, equal to exactly 1.3558179483314004 joules — the work done by one pound-force acting through one foot. It is common in US mechanical and ballistics contexts, where it is distinct from the pound-foot unit of torque despite sharing the same underlying units.
The joule (J) is the SI derived unit of energy, work, and heat — defined as the energy transferred when a force of one newton acts over one meter. The joule is the standard unit in physics, chemistry, and most modern engineering documentation.
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