Work Calculator

How it works

1. 1Enter the applied force, the displacement distance, and the angle θ between the force and the direction of motion.
2. 2The calculator converts your inputs to SI units and applies W = F·d·cosθ, where cosθ takes only the force component along the displacement.
3. 3Results appear instantly in joules, kilojoules, and foot-pounds — switch between metric and imperial at the top.

Use cases

• Physics students solving mechanics problems with forces at an angle, such as a sled pulled by a rope.
• Engineers estimating the energy needed to move a load a given distance against friction or gravity.
• Biomechanics — calculating the work done when lifting a weight or pushing an object across a surface.

Frequently asked questions

What is the formula for mechanical work?

Work is W = F·d·cosθ, where F is force in newtons, d is displacement in metres, and θ is the angle between the force and the motion. For example, 10 N applied over 5 m in the same direction (θ = 0°) gives W = 10 × 5 × cos0° = 50 J.

Why is work zero when the force is perpendicular to motion?

When θ = 90°, cos90° = 0, so W = 0 J. Carrying a box horizontally is a classic case: gravity pulls straight down, perpendicular to the horizontal motion, so gravity does no work on the box.

What is the difference between joules and foot-pounds?

1 kilojoule = 1000 joules, useful for larger values. 1 foot-pound ≈ 1.356 J — the imperial unit of work used in the US. The calculator shows all three at once so you can pick whichever suits your context.