About this tool
The Work, Energy & Power Calculator is a free, in-browser mechanics tool. Work mode uses W = F·d·cosθ — the work done by a force F acting over a displacement d at angle θ between them — and can solve for work, force, displacement or the angle. Power mode uses P = W/t to solve for power, work or time.
Units are SI: force in newtons, displacement in metres, angle in degrees, work in joules and power in watts, with time in seconds. This tool covers mechanical work and power specifically, distinct from electrical power tools.
All figures are computed locally in your browser and update live as you type, so you can see immediately how the angle between force and motion changes the work done.
Frequently asked questions
What does the angle θ mean and what units are used?
θ is the angle in degrees between the force and the displacement. Force is in newtons, displacement in metres, work in joules and power in watts (time in seconds).
Why is work zero when θ = 90°?
Because W = F·d·cosθ and cos90° = 0. A force perpendicular to the motion — like the normal force or a satellite's central gravity — does no work on the object.
How is power related to work?
Power is the rate of doing work, P = W/t. One watt equals one joule per second, so lifting the same weight faster requires more power even though the work is the same.
How is this different from an electrical power calculator?
This tool covers mechanical work and power (force × distance, work ÷ time). Electrical power (P = V·I) is handled separately; the formulas and units here are purely mechanical.