Work Calculator (W = Fs)
Solve the physics work formula W = Fs for work, force, or distance. Enter any two values and the calculator solves the third with step-by-step working.
The work formula
In physics, work is the energy transferred when a force moves an object through a distance:
- W — work, in joules (J)
- F — force applied in the direction of motion, in newtons (N)
- s — distance moved in the direction of the force, in metres (m)
Enter any two values and leave the third blank; the calculator solves for it and shows the substitution step.
Worked example
A 50 N force pushes a crate 4 m across a floor. How much work is done?
- Formula: W = Fs
- Substitute: W = 50 × 4
- Result: W = 200 J
Solving in reverse
The same formula rearranges to find force or distance when work is known:
- Force: F = W / s — enter W and s, leave F blank.
- Distance: s = W / F — enter W and F, leave s blank.
For example, 200 J of work over a 4 m distance means F = 200 / 4 = 50 N. And 200 J done by a 50 N force means s = 200 / 50 = 4 m.
Common mix-ups
- Confusing work with force. Force (N) is a push or pull; work (J) is how much energy that push or pull transfers over a distance — no distance moved means no work done, no matter how large the force.
- Ignoring direction. Only the force component along the direction of motion counts. Pushing straight down on a cart that only moves horizontally does zero work in this simple formula.
- Mixing units. Foot-pounds, calories, or ergs must be converted to joules, newtons, and metres before using this calculator.
Where this shows up
Work is the bridge between force and energy: the kinetic energy gained by a moving object equals the net work done on it (the work-energy theorem), and lifting a mass against gravity stores that work as gravitational potential energy. Work also underlies power (work per unit time) and connects directly back to force itself — see also momentum and pressure for other force-based quantities.
Frequently asked questions
- What is the formula for work in physics?
- Work equals force times distance: W = Fs, where W is work in joules (J), F is the force in newtons (N), and s is the distance moved in the direction of that force, in metres (m).
- How do I find the force if I know the work and distance?
- Rearrange the formula to F = W / s. Enter the work and distance values and leave the force field blank, and the calculator solves it for you automatically.
- What units does work use?
- SI units throughout — joules (J) for work, newtons (N) for force, and metres (m) for distance. Convert other units (foot-pounds, ergs, centimetres) to SI before entering them.
- Is work the same thing as energy?
- Yes — work and energy share the same unit, the joule. Work is the amount of energy transferred to or from an object by a force acting through a distance.
- Why can't I leave two fields blank?
- The calculator solves for exactly one unknown from the other two known values. With two blanks there are infinitely many (F, s) pairs that give the same W, so leave only the single variable you want solved blank.
- What if the force and the distance moved are in different directions?
- This calculator assumes the force acts along the direction of motion. If the force is at an angle, only the component of force along the displacement does work — that case needs W = Fs·cos(θ), which is outside this simple form.
- Can work be negative?
- Yes. If the force acts opposite to the direction of motion (like friction slowing an object down), the work done on the object is negative.