Key takeaways
- Work done is W = F × d: force times distance, measured in joules.
- No movement in the direction of the force means zero work, however hard you push.
- Only the distance moved *in the direction of the force* counts.
- Work and energy share the same unit, the joule, because doing work is how energy transfers.
In this guide
What is work done?
Work is done whenever a force causes something to move in the direction of that force. The larger the force, or the further the object moves, the more work is done, and the more energy is transferred.
Why does work done matter?
Work is how physics measures energy transfer. Every time something moves because of a push or pull, work is being done, and that idea underlies machines, muscles, and motors alike.
Push a stalled car for 10 minutes without it moving an inch, and physics says you've done zero work, even though your muscles used plenty of energy doing it.
The formula
| Symbol | What it means | Example |
|---|---|---|
| W | The work done, in joules (J) | 200 J |
| F | The force applied, in newtons (N) | 50 N |
| d | The distance moved in the direction of the force, in metres (m) | 4 m |
How to calculate work done step by step
- 1Find the force. Measure it in newtons.
- 2Find the distance moved. Measure it in metres, only counting movement in the direction of the force.
- 3Multiply force by distance.
F × dgives you the work done. - 4Write the answer in joules.
Try the calculator below with your own force and distance to see every step worked out.
Try it yourself
Pre-filled with the example — change any value.
Common mistakes to avoid
- Using the wrong distance. Only the distance moved in the direction of the force counts, not any sideways or unrelated movement.
- Mixing up work and power. Work is the total energy transferred; power is how quickly that energy is transferred.
- Forgetting units. Force must be in newtons and distance in metres for the answer to come out in joules.
Tips and tricks
- Working backwards from work to force? Divide by distance:
F = W ÷ d. - If a force acts at an angle to the motion, only the part of the force in the direction of travel counts — this calculator assumes the force and motion line up.
- Work done connects directly to force, since you need a force before you can do any work at all.
Where you'll use it in real life
- Moving furniture: work done explains how much energy it takes to drag a sofa across a room.
- Machines: motors and engines are rated partly by how much work they can do in a given time.
- Lifting: cranes and elevators do measurable work against gravity every time they lift a load.
- Sport: rowing, cycling, and weightlifting all involve doing measurable work against resistance.
Quick summary
To find work done, multiply the force applied in newtons by the distance moved in the same direction, in metres. No movement means no work, no matter how much force is involved. Use the calculator above to check your own example.
Worked example
You push a 50 N (newton) force on a box and slide it 4 metres across a warehouse floor. How much work do you do?
- 01W = F × d
- 02W = 50 × 4
- 03W = 200 J
These numbers are pre-filled in the calculator above.
Frequently asked questions
How do I calculate work done?
Multiply the force applied in newtons by the distance moved in metres: W = F × d. The result is in joules.
Is work done the same as energy?
Yes. In physics, work and energy are measured in the same unit, joules, because doing work is exactly how energy transfers from one thing to another.
Why is no work done if nothing moves?
Work requires movement in the direction of the force. Without any distance moved, the formula gives zero, even if a lot of effort was used.
What's the difference between work and power?
Work is the total energy transferred by a force over a distance. Power is how quickly that work is done, measured in watts.
