Work Energy Calculator

Calculate work done by a force using W = Fd cos(θ). Includes Work-Energy Theorem (ΔKE = W), gravitational PE, friction work, efficiency, and mechanical advantage.

N
m
°
Work Done (J)
Work Done (kJ)
Work Done (ft-lb)
Extended More scenarios, charts & detailed breakdown
N
m
°
Work (J)
Work (kJ)
Effective Force Component
Professional Full parameters & maximum detail
N
m
°
kg
J

Work Components

Work by Applied Force (J)
Work Against Friction (J)
Net Work (J)

Efficiency & Type

Efficiency (%)
Force Type

How to Use This Calculator

  1. Enter Force (N), Distance (m), and the Angle between force and displacement.
  2. Click Calculate to see work in Joules, kJ, and ft-lb.
  3. Use the Work-Energy Theorem tab to find net work from velocity change.
  4. Use the Gravitational PE tab to compute mgh work.
  5. The Professional tab adds friction work, net work, and efficiency calculation.

Formula

W = F × d × cos(θ)  |  ΔKE = W_net = ½mv₂² − ½mv₁²  |  W_gravity = mgh

Example

F=50 N, d=10 m, θ=0° → W = 50×10×cos(0°) = 500 J = 0.5 kJ = 368.78 ft-lb.

Frequently Asked Questions

  • Work = Force × Distance × cos(θ), where θ is the angle between the force direction and displacement. When force and displacement are parallel (θ=0°), cos(0°)=1, so W = F × d.
  • The Work-Energy Theorem states that the net work done on an object equals its change in kinetic energy: W_net = ΔKE = ½mv₂² − ½mv₁². This means work and energy are interchangeable.
  • The SI unit of work is the Joule (J), where 1 J = 1 N·m = 1 kg·m²/s². In imperial units, work is measured in foot-pounds (ft-lb). 1 J ≈ 0.7376 ft-lb.
  • Only the component of force parallel to displacement does work. At 0° (force parallel to motion), all force contributes: W = Fd. At 90° (force perpendicular), cos(90°)=0, so no work is done despite the force.
  • Work is the energy transferred (W = Fd cos θ, in Joules). Power is the rate at which work is done (P = W/t, in Watts). Same work done faster requires more power.

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