In this displacement calculator, we will show you how to find displacement in a matter of seconds. We will also help you understand the displacement definition, and the displacement formula while we're at it.

What is displacement? What is the difference between displacements vs. distance? How to calculate displacement in physics? Find all the answers here!

Displacement definition: what is displacement?

Let's start from the beginning with the displacement definition. Displacement means different things in different contexts, so what is displacement in physics? In physics (and geometry), displacement is the amount an object has moved regardless of the path taken.

We will see this better when we look at the displacement formula, but displacement can be thought of as the distance between the starting point and the finishing point. It doesn't take into account the path taken to get from one point to the other, so it doesn't measure the distance traveled.

visual displacement definition

The distance you have to travel from New York to Washington depends on the route you take, but no matter what road you choose, the final displacement will always be the same: the straight-line distance from one city to the other.

How to calculate displacement: displacement formula

So, how to calculate displacement if it isn't the same as the distance traveled? The first thing to do is look at the displacement formula, and forget about the displacement vs. distance debates. There are many formulations of the displacement formula, but the one we are interested in is this:

d = v * t

where,

  • d is the displacement;
  • t is the time taken from start to finish; and
  • v is the average velocity between the points.

Velocity is the crucial point here; we're not talking about speed. Velocity takes into account the direction of motion.

Since we are talking about displacement in physics, we can also calculate the average velocity using the acceleration calculator, or the acceleration formula (if acceleration is constant):

a = 1/2 * (vf - vi)

where,

  • a is the acceleration;
  • vi is the initial velocity; and
  • vf is the final velocity.

We can then make displacement:

d = 1/2 * a * t2 + vi * t

Alternatively, we could calculate the average velocity from a collection of velocities by doing a weighted average of them, where the weight of each velocity is the time spent at that velocity.

How to find displacement using the displacement calculator?

In the displacement calculator that you see on your left, we have implemented three modes. The default, and most straightforward, way to find the displacement is by using a constant velocity. Increasing in complexity (and in number of inputs required), we next have a method that lets you calculate displacement by using the initial and final velocities, or the acceleration.

In the third mode of the displacement calculator, you can input up to 10 different velocities (and their respective times), and it will calculate the total displacement for you. As you fill one velocity in, a new one will appear.

Here is an example of how to find displacement from the acceleration and time:

  1. Input the time the object is in movement.
  2. Input the acceleration.
  3. Input the initial or final velocity.
  4. Watch as the resulting displacement is calculated for you.

As a bonus, we will also find the final/initial velocity for you.

Now that you've learned how to calculate the displacement, you might be wondering how it differs from the distance; we have you covered!

Displacement vs. distance; differences and similarities

Displacement and distance are often confused, mostly because, in our daily lives, we always refer to both as distance. Displacement in physics (and geometry) is a slight different, in a very similar way as velocity differs from speed.

A logical way to think about the displacement vs. distance dilemma is that displacement is to velocity what distance is to speed. When you are using direction-less speed, you get distance, so the length of the path traveled. On the other hand, using a vector-like velocity gets you the difference in position between the start and finish: displacement.

Even though distance is the most practical quantity in our normal lives, in physics, displacement takes center stage. Quantities like work depend on force and displacement, but not on distance.

Álvaro Díez