MotionLab
Work Calculator
W = F · d, in joules.
Work done by a force over a distance
Work is force times distance moved in the direction of the force. One joule is one newton acting over one metre.
| Force (N) | Distance (m) | Work (J) | Context |
|---|---|---|---|
| 9.81 | 100 | 981.00 | Lifting 1 kg by 100 m |
| 10 | 1 | 10.00 | Definition scale |
| 50 | 20 | 1000.00 | Pushing a box 20 m |
| 100 | 5 | 500.00 | Moderate push |
| 500 | 2 | 1000.00 | Heavy lift |
| 1000 | 10 | 10000.00 | Winching a load |
Rows three and five both give 1,000 J from very different forces, since only the product matters. The crucial condition is that the distance must be in the direction of the force: carrying a suitcase horizontally does no work against gravity at all, however tiring it feels, because the force is vertical and the motion is not. Holding something still also does zero work in the physics sense. Work and energy share the joule because work is precisely the transfer of energy.
Work only counts along the direction of motion
In physics, 'work' has a strict meaning: force applied over a distance in the direction of motion — holding a heavy box still, no matter how tiring, does zero physics work because there's no displacement.
Work and energy are the same currency
The work-energy theorem says the net work done on an object equals its change in kinetic energy — work is literally the mechanism by which energy transfers into or out of a moving object.
Frequently asked questions
I push a 50 kg box 10 meters across a floor with 200 N of force. How much work did I do?
W = F × d = 200 × 10 = 2,000 joules = 2 kJ. That's assuming the force is in the direction of motion. If you push at an angle θ, multiply by cos(θ) — pushing at 30° gives W = 200 × 10 × cos(30°) = 1,732 J.
Why is holding a heavy object not 'work' in physics?
Physics work requires displacement. Holding a 20 kg weight overhead, your muscles burn energy (biological work) but the weight doesn't move — displacement = 0, so W = F × 0 = 0 joules. The energy goes to heat in your muscles, not into the object.
How is work related to power?
Power = work ÷ time. Doing 2,000 J of work in 10 seconds = 200 watts. In 2 seconds = 1,000 watts. Same work, different power. Power measures how fast you do work, not how much. See the power calculator for time-based problems.
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Last updated: September 6, 2026