In physics, work is done when a force moves something along its direction. Carrying a box horizontally does no work on it against gravity, while lifting it does. The work–energy theorem says the net work equals the change in kinetic energy.
How to use the Work Calculator
- Calculate from…
- Force F
- Angle between force and motion θ
- Displacement d
- Mass m
- Initial velocity v₀
- Final velocity v₁
- Time taken (optional)
Results update as you type, every field has its own unit menu, and everything is calculated in your browser.
How it works
Choose force and displacement (with the angle between them) or the kinetic energy change. Add a time to see the average power.
Inputs explained
| Field | What to enter |
|---|---|
| Calculate from… | Choose one: Force and displacement, Change in kinetic energy |
| Force F | Units: N, kN, MN, mN, lbf, kgf … |
| Angle between force and motion θ | Units: °, rad, arcmin, arcsec, mrad |
| Displacement d | Units: m, cm, mm, km, in, ft … |
| Mass m | Units: kg, g, mg, t, lb, oz |
| Initial velocity v₀ | Units: m/s, km/h, mph, ft/s, knots, km/s |
| Final velocity v₁ | Units: m/s, km/h, mph, ft/s, knots, km/s |
| Time taken (optional) | Units: s, ms, min, h, days |
Example values
How the main result changes when Force F changes and everything else stays at the example values above:
| Force F (N) | Work done (J) |
|---|---|
| 50 | 500 |
| 75 | 750 |
| 100 | 1,000 |
| 125 | 1,250 |
| 150 | 1,500 |
| 200 | 2,000 |
Formula
W = F·d·cos θ · W = ½m(v₁² − v₀²) · P = W/t
Worked example
Inputs: Calculate from…: Force and displacement; Force F: 100 N; Angle between force and motion θ: 0 °; Displacement d: 10 m; Time taken (optional): 5 s.
Results: Work done = 1,000 J; Average power = 200 W.
Key terms
- Work
- Energy transferred by a force acting along a displacement.
Frequently asked questions
Is work done when carrying a box horizontally?
Not against gravity, because the force is perpendicular to the motion.
Can work be negative?
Yes, when the force opposes the motion, like friction.
What is the unit of work?
The joule: 1 N acting over 1 m.
What is the work–energy theorem?
Net work equals the change in kinetic energy.