Enter the force (N) and the distance (m) (and optionally the angle) into the calculator to determine the work (energy transferred). If you know speed and time instead of distance, use the Power/Time tab.

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)