Distance-Time Graphs

Distance-time graphs help us visualise how far an object travels in a given period of time. Below is an example of a distance-time graph.

The time in seconds (s) is always on the x-axis and the distance in metres (m) is always on the y-axis.


The gradient of the line on a distance-time graph indicates the speed of the object. The steeper the line, the faster the object’s speed.

  • We can calculate the gradient at different points on the graph to find out the speed of the object at different points in time.

Therefore, the gradient of the line is:

The delta symbol (Δ) means change. So in this case, ΔD means a change in distance and ΔT means a change in time.

Characteristics of Distance-Time Graphs

When looking at a distance-time graph, we can identify important characteristics:

  • Straight lines indicate a constant speed (constant gradient)
  • Horizontal lines indicate a stationary object (the object has stopped and the gradient is 0)
  • A curve that becomes steeper indicates an accelerating object (increasing gradient)
  • A curve that becomes flatter indicates a decelerating object (decreasing gradient)