What is Dual Axis?

A dual axis shows two measures in one view on two independent axes, drawn on top of one another rather than side by side.

Each measure keeps its own Marks card, so you can render one as bars and the other as a line — the standard actual-against-target chart.

Create it by dragging the second measure to the opposite edge of the view, or by right-clicking the second pill and choosing Dual Axis.

The thing to be careful about is the scales. Two independent axes can be positioned to suggest almost any relationship, so where both measures share a unit you should right-click the secondary axis and Synchronise Axis. If they share a unit and a similar range, a blended axis is often the more honest choice.