How to Create a Combined Axis Chart in Tableau

Creating a combined axis chart is one of the quickest ways to compare multiple measures against the same scale in Tableau. Unlike its cousin, the dual-axis chart, a combined axis chart simplifies your view by placing different data series onto a single, shared axis. This article will walk you through exactly how to build, customize, and effectively use a combined axis chart for clearer data analysis.

What Exactly is a Combined Axis Chart?

A combined axis chart, also known as a blended axis chart, visualizes multiple measures along a single continuous axis. Tableau achieves this by creating a single "Measure Values" field that contains all the measures you want to display and a "Measure Names" field to differentiate between them, typically with color or shape. Think of it as laying multiple charts on top of each other, all sharing the same y-axis (or x-axis).

The most common use case is comparing measures that share the same unit and have a similar magnitude. For instance, plotting Sales and Profit over time on one axis makes instant sense because profit is a component of sales, and both are measured in dollars. This lets you immediately see the relationship and gap between the two.

When Should You Use a Combined Axis Chart?

While versatile, combined axis charts shine in specific scenarios. You'll get the most value when you need to:

• Compare parts to a whole: Visualizing component metrics alongside a total metric is a classic use case. Examples include comparing a specific campaign's ad spend to the total marketing budget or looking at profit vs. revenue.
• Analyze related metrics with the same scale: If you're tracking forecasted sales vs. actual sales, both are in dollars, making them perfect candidates for a combined axis. Another example is tracking new users vs. returning users over time.
• Reduce clutter in a dashboard: Instead of creating two separate charts for two closely related measures, a combined axis chart occupies less space while making the relationship between the measures easier to spot.

The key is that the measures should be contextually related and comparable on the same scale. If one measure is in the millions and another is in the hundreds, the smaller one will appear as a flat line and its pattern will be lost. In that case, a dual-axis chart would be better suited.

How to Build a Combined Axis Chart in Tableau: A Step-by-Step Guide

We'll use Tableau's "Sample - Superstore" dataset. Imagine our goal is to compare our sales performance against our profit each month.

Step 1: Create your base visualization

First, let's build a simple line chart showing sales over time. This will be the foundation of our combined axis chart.

1. Drag Order Date from the Data pane and drop it onto the Columns shelf.
2. Right-click the "Order Date" pill and change it from YEAR to Month (the second, an aggregated MONTH(Order Date), not the first discrete MONTH).
3. Drag the Sales measure onto the Rows shelf.

You now have a basic line chart displaying total sales for each month.

Step 2: Add the second measure to the same axis

This is where the magic happens. To create the combined axis, we need to add our second measure, Profit, to the existing Sales axis.

1. Find the Profit measure in the Data pane.
2. Drag Profit over to the view. Instead of dropping it on the Rows shelf next to Sales, drag it directly over the existing Sales axis (the vertical axis) on the left side of your chart.
3. Hold it there until you see a faint icon of two parallel green bars. This is Tableau's signal that it's ready to create a combined axis. Once you see the icon, release the mouse button.

Tableau will instantly transform your chart.

Step 3: Understand the "Measure Values" & "Measure Names" fields

As soon as you created the combined axis, Tableau made some changes for you automatically. Look at your shelves and Marks card:

• The Sales pill on the Rows shelf has been replaced by a pill called Measure Values.
• The Marks card now contains a new filter for Measure Names (showing which measures are included) and a Measure Names pill on the Color shelf.

So, what just happened? Tableau consolidated your two measures (Sales and Profit) into a single container called 'Measure Values'. To tell the lines apart, it created a dimension called 'Measure Names' which holds the names "Sales" and "Profit" and assigned a different color to each. This is the fundamental mechanic of a combined axis chart.

Step 4: Customize your blended chart

Now that you have your combined axis chart, let's make it more insightful. A great way to visualize a part-to-whole relationship like Sales vs. Profit is to display the total (Sales) as a bar chart and the component (Profit) as a line chart.

1. On the Marks card, you will see an entry for "Measure Values." Click on the dropdown that currently says 'Automatic' and change the mark type to Bar. This turns both lines into bars.
2. Now, locate the Measure Names pill (it should be on the Color shelf). Drag this pill onto the Size shelf. This gives you two different sized bars for each month.
3. That's still not quite what we want. To have different chart types, we need a small trick. Instead, let's go back. Undo your last two actions (Ctrl+Z) to get back to the two line charts.
4. An easier way is to click the dropdown next to the "Measure Values" on the Marks card. This gives you control over all marks. Instead of changing that, locate the list of Measures under the Marks card. Click on 'Profit', and in the dropdown for its marks, change from 'Automatic' to 'Line'. Go back to your 'Sales' measure in that same list and change the mark type on 'Sales' to 'Bar'.
5. Or, here's an even better method: Click on the dropdown on the "SUM(Sales)" mark within the Measure Values card which lives below the marks card, and change its individual mark type to Bar. Keep "SUM(Profit)" as a Line. Now you have a clear bar chart representing sales, with a line layered on top showing the profit for each month.
6. Refine the appearance: You can edit the colors by clicking on the Color shelf. You can also adjust the bar size by clicking on the Size shelf to make the visuals clearer.

This combination view makes it instantly obvious how much profit you're generating relative to total sales in any given month.

Combined Axis vs. Dual Axis Charts: Knowing the Difference

This is one of the most common points of confusion for Tableau newcomers. While they look similar, their underlying structure and use cases are distinct.

Combined Axis Chart:

• Structure: A single, shared Y-axis for all measures.
• Creation: Dragging a new measure onto an existing axis.
• Shelves: Creates 'Measure Values' and 'Measure Names' fields.
• Best for: Comparing measures with the same unit and a similar scale (e.g., Sales vs. Profit, Website Visitors vs. Unique Visitors). The axes are always synchronized because there is only one.

Dual Axis Chart:

• Structure: Two independent Y-axes, one on the left and one on the right.
• Creation: Dragging a new measure to the opposite side of the view or right-clicking a pill on the Rows shelf and selecting "Dual Axis".
• Shelves: Keeps two separate measure pills on the Rows shelf.
• Best for: Comparing measures with very different scales or units (e.g., Sales in dollars vs. Quantity of items sold, or Website Traffic vs. Clicks). You must remember to synchronize the axes unless you have a good reason not to.

Final Thoughts

Building a combined axis chart in Tableau is a simple yet powerful technique to compare related measures efficiently. By dragging one measure directly onto another measure's axis, you can instantly see them on a single, shared scale, making it perfect for part-to-whole analysis without cluttering your dashboard.

While mastering tools like Tableau unlocks powerful data insights, we know the learning curve can be steep for busy teams. Answering a simple business question shouldn't require clicking through dozens of menus or wrangling fields like 'Measure Values'. We built Graphed to remove that friction. By connecting your data sources and allowing you to just ask for what you want in plain English - like "show me sales vs profit by month" - we help you get straight to the insights, creating real-time, interactive dashboards in seconds, not hours.