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Foot-pounds (energy) to Joules Converter

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.

How to convert foot-pounds (energy) to joules

  1. Take your value

    Start with your value in foot-pounds (energy).

  2. Multiply by 1.35582

    Multiply the foot-pound (energy) value by 1.35582. This is the exact conversion factor from foot-pounds (energy) to joules.

  3. Read the result

    The product is your value in joules. For example, 5 ft·lbf × 1.35582 = 6.77909 J.

Conversion formula

The exact factor from foot-pounds (energy) to joules is 1.35582.

Joules = Foot-pounds (energy) × 1.35582

Foot-pounds (energy) to Joules conversion table

Fifty common reference values, hand-picked for skim utility. Use the calculator above for any value not listed.

Conversion table from foot-pounds (energy) to joules
Foot-pounds (energy) (ft·lbf)Joules (J)
0.001 ft·lbf0.0013558 J
0.01 ft·lbf0.013558 J
0.1 ft·lbf0.13558 J
0.5 ft·lbf0.67791 J
1 ft·lbf1.3558 J
1.5 ft·lbf2.0337 J
2 ft·lbf2.7116 J
5 ft·lbf6.7791 J
10 ft·lbf13.558 J
20 ft·lbf27.116 J
50 ft·lbf67.791 J
100 ft·lbf135.58 J
200 ft·lbf271.16 J
250 ft·lbf338.95 J
500 ft·lbf677.91 J
1000 ft·lbf1355.8 J
2000 ft·lbf2711.6 J
2500 ft·lbf3389.5 J
3600 ft·lbf4880.9 J
5000 ft·lbf6779.1 J
7500 ft·lbf10169 J
10000 ft·lbf13558 J
25000 ft·lbf33895 J
50000 ft·lbf67791 J
100000 ft·lbf135582 J
250000 ft·lbf338954 J
500000 ft·lbf677909 J
1000000 ft·lbf1355818 J
2000000 ft·lbf2711636 J
3600000 ft·lbf4880945 J
5000000 ft·lbf6779090 J
10000000 ft·lbf13558179 J
25000000 ft·lbf33895449 J
50000000 ft·lbf67790897 J
100000000 ft·lbf135581795 J
250000000 ft·lbf338954487 J
500000000 ft·lbf677908974 J
1000000000 ft·lbf1355817948 J
2000000000 ft·lbf2711635897 J
5000000000 ft·lbf6779089742 J
10000000000 ft·lbf13558179483 J
20000000000 ft·lbf27116358967 J
50000000000 ft·lbf67790897417 J
100000000000 ft·lbf135581794833 J
1000000000000 ft·lbf1355817948331 J
10000000000000 ft·lbf13558179483314 J
100000000000000 ft·lbf135581794833140 J
1000000000000000 ft·lbf1.3558 × 10^15 J
10000000000000000 ft·lbf1.3558 × 10^16 J
100000000000000000 ft·lbf1.3558 × 10^17 J

Real-world reference

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.

Frequently asked questions

How many joules are in 1 foot-pound (energy)?
1 foot-pound (energy) equals 1.35582 joules.
How do I convert foot-pounds (energy) to joules?
Multiply the foot-pound (energy) value by 1.35582. So x ft·lbf × 1.35582 = the equivalent in J.
What is 5 foot-pounds (energy) in joules?
5 foot-pounds (energy) equals 6.77909 joules.
What is 10 foot-pounds (energy) in joules?
10 foot-pounds (energy) equals 13.5582 joules.
What is 100 foot-pounds (energy) in joules?
100 foot-pounds (energy) equals 135.582 joules.
How do I convert back from joules to foot-pounds (energy)?
Multiply the joule value by 0.737562. For example, 1 J = 0.737562 ft·lbf.
Is the foot-pound (energy) bigger than the joule?
Yes. 1 foot-pound (energy) is larger than 1 joule — specifically 1.35582 times larger.
Are these conversion factors exact?
The underlying imperial/US unit definitions are exact; the displayed factor (1.35582) is rounded for readability, and the browser computes using IEEE 754 double-precision arithmetic.

About the foot-pound (energy) and the joule

The foot-pound (energy)

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

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.

Sources