Calculate work and energy from force, distance, and angle, plus power, kinetic energy, or rotational work with unit conversions for all modes.

Force to Energy Calculator

Work (F·d·cosθ)
Power/Time
Kinetic Energy
Rotational Work

Enter any two of Force, Distance, or Energy. Angle is optional (defaults to 0°).

Energy from Force Formula

The following equation is used to calculate the Energy from Force.

E = F*d*cos(θ)
  • Where E is the work done (energy transferred) (Joules)
  • F is the applied force (N)
  • d is the displacement (m)
  • θ is the angle between the force and the displacement

To calculate energy (work) from a force, multiply the force by the displacement and by cos(θ). When the force is along the direction of motion, θ = 0° and the formula simplifies to E = F·d.

Foot‑pound force to Joules Conversion Table (1 ft·lbf = 1.35582 J)
Foot‑pound force (ft·lbf) Joules (J)
0.250.339
0.50.678
11.356
22.712
56.779
1013.558
1520.337
2027.116
2533.895
3040.675
4054.233
5067.791
75101.686
100135.582
150203.373
200271.164
250338.954
300406.745
500677.909
10001355.818
Conversions use 1 ft·lbf = 1.355817948 J (exact to 6 dp shown). Inverse: 1 J ≈ 0.737562 ft·lbf.

How to Calculate Energy from Force?

The following example problems outline the steps and information needed to calculate the Energy from Force.

Example Problem #1

  1. First, determine the total force (N). In this example, the total force is 4 N.
  2. Next, determine the distance (m). For this problem, the distance is 8 m.
  3. Next, determine the angle between the force and displacement. In this case, the force is along the direction of motion, so θ = 0°.
  4. Finally, calculate the Energy from Force using the formula above.

E = F*d*cos(θ)

Inserting the values from above and solving the equation yields: 

E = 4*8*cos(0°) = 32 (Joules)


Example Problem #2

Using the same method as above, first, we need to measure or determine the variables required by the equation. For this example problem, these are provided as follows: 

total force (N) = 9

distance (m) = 4

angle (θ) = 0°

Enter these given values into the calculator or the formula above yields: 

E = 9*4*cos(0°) = 36 (Joules)