Dual axis charts in Tableau - Step-by-Step Guide

Introduction

Dual axis charts let you show two different measures on the same chart using two vertical axes. This helps compare related data with different scales clearly in one view.

When you want to compare sales revenue and number of units sold on the same timeline.

When you need to show temperature and rainfall together on a weather dashboard.

When you want to display profit margin and total sales side by side for each product category.

When you want to combine actual sales and sales target in one chart for easy comparison.

When you want to visualize website visits and conversion rate on the same graph.

Steps

Step 1: Drag the first measure (e.g., Sales) to Rows shelf

- Rows shelf

A single-axis chart with the first measure appears on the view

Step 2: Drag the second measure (e.g., Profit) to the right side of the existing axis on Rows shelf

- Rows shelf, next to the first measure

Two separate charts appear stacked vertically, each with its own axis

Step 3: Right-click the second measure's axis and select 'Dual Axis'

- Second measure's axis on the view

Both measures share the same horizontal axis but have separate vertical axes, overlapping in one chart

Step 4: Click the drop-down arrow on the Marks card and select each measure to customize colors or chart types

- Marks card

Each measure can have different colors or chart types (e.g., bars and lines) for clarity

Step 5: Right-click one of the axes and select 'Synchronize Axis' if scales should match

- One of the vertical axes

Both axes use the same scale, making comparison easier

Step 6: Format axes and labels as needed for clarity

- Axes and Labels on the view

The chart looks clear and easy to read with proper labels and formatting

Before vs After

Before

Two separate charts stacked vertically: Sales with axis 0-10000, Profit with axis 0-2000

After

One combined chart with Sales and Profit overlaid, each with its own vertical axis on left and right

Settings Reference

Dual Axis

📍 Right-click on second measure's axis in the view

Combine two measures on one chart with two vertical axes

Default: Separate Axis

Synchronize Axis

📍 Right-click on one of the vertical axes

Make both axes use the same scale for easier comparison

Default: Unsynchronize

Marks Type

📍 Marks card for each measure

Choose how each measure is visually represented on the chart

Default: Automatic

Common Mistakes

Not selecting 'Dual Axis' after adding the second measure

The measures remain in separate charts stacked vertically, not combined

Right-click the second measure's axis and choose 'Dual Axis' to overlay them

Forgetting to synchronize axes when scales are similar

Axes have different scales, making visual comparison confusing

Right-click one axis and select 'Synchronize Axis' to align scales

Using the same mark type and color for both measures

It becomes hard to distinguish which data belongs to which measure

Use different mark types or colors for each measure on the Marks card

Summary

Dual axis charts overlay two measures with separate vertical axes on one chart.

They help compare related data with different scales clearly in one view.

Remember to use 'Dual Axis' and optionally 'Synchronize Axis' for best clarity.