How to Add Dots to Line Graph in Tableau

A simple line graph in Tableau is great for showing trends, but sometimes the most important details are the individual data points themselves. Adding dots, or markers, to your line graph can instantly make it easier to read and highlight key moments in your data. This article guides you through two straightforward methods to add these markers to your line graphs in Tableau.

Why Add Markers to Your Tableau Line Graph?

Before diving into the "how," it's helpful to understand the "why." A standard line graph connects data points to show the general direction of a trend, but the line itself can sometimes obscure the exact points where data was recorded. Adding dots gives you the best of both worlds.

• Improved Readability: Markers pinpoint the exact values on your chart, making it easier for your audience to see specific figures, especially on a graph with fewer data points.
• Highlighting Data Points: Dots draw the eye to individual measurements. This is perfect for calling out monthly sales figures, daily website sessions, or specific campaign results.
• Enhanced Visual Appeal: A line with markers often looks more polished and intentionally designed, giving your dashboard a more professional feel.
• Clearer Analysis: It becomes much easier to spot outliers or significant jumps between periods when the points are clearly marked.

First, Let's Build a Basic Line Graph

To demonstrate, we'll use the "Sample - Superstore" dataset that comes with Tableau. Our goal is to create a simple line graph showing sales over time. This will be our starting point.

1. Connect to the "Sample - Superstore" data source.
2. Drag the Order Date field to the Columns shelf. Tableau will likely default it to YEAR(Order Date). Right-click the blue pill and change it to show the continuous Month (the second month option in the list).
3. Drag the Sales measure to the Rows shelf.

You should now have a standard line graph charting sales by month. Now, let's add some dots to it.

Method 1: The Quick and Easy Dual Axis Technique

The dual axis method is the most common and flexible way to add markers to a line graph in Tableau. It might sound complicated, but it only takes a few clicks. It works by overlaying two separate charts - one line chart and one dot plot (a scatter plot) - on top of each other.

Step 1: Duplicate Your Measure

With your basic line graph from the previous step on the screen, drag the Sales measure from the Data pane and drop it onto the Rows shelf again, right next to the existing SUM(Sales) pill. You will now see two identical line graphs, one above the other.

Step 2: Create the Dual Axis Chart

Now, we'll combine these two charts. Right-click the second SUM(Sales) pill on your Rows shelf and select Dual Axis from the dropdown menu. Your two line graphs will merge into a single chart area with two Y-axes, one on the left and one on the right.

Step 3: Synchronize the Axes

You may notice the scales on your two Y-axes aren't identical. This can misrepresent the data. To fix it, right-click the right-hand axis and select Synchronize Axis. Now both axes will share the exact same scale, and your visuals will be accurately aligned.

Step 4: Change the Mark Type to Circles

This is where the magic happens. Look at your Marks card. You'll now see three tabs: "All," "SUM(Sales)," and "SUM(Sales) (2)." These tabs allow you to control the cosmetic properties of each chart independently.

• Click on the second marks tab, SUM(Sales) (2).
• On this card, click the dropdown menu that currently says "Automatic."
• Change it to Circle.

And there you have it! The second chart is no longer a line but a series of circles plotted at each data point, perfectly overlaid on top of your original line graph. You now have a line graph with dots.

Step 5: Clean Up and Customize

To finalize your chart, you can hide the unnecessary right-hand axis. Right-click on it and uncheck Show Header.

From here, you can customize the line and the dots independently. For example, on the first SUM(Sales) marks card, you can make the line thinner or a lighter color. On the second SUM(Sales) (2) marks card, you can click on Size to make the circles bigger or on Color to make them stand out.

Method 2: The Simpler All-in-One Marker Setting

If you don't need independent control over your line and your dots, Tableau has a built-in setting that can accomplish this even faster. It’s slightly less flexible but works perfectly for quick additions.

Step 1: Start with Your Basic Line Graph

Let’s go back to the original simple line graph we created (Order Date on Columns, Sales on Rows).

Step 2: Edit the Color Mark Properties

On the Marks card, click on the Color tile. This opens a small settings window.

Step 3: Add Markers

Inside this window, look for the Markers section under "Effects." By default, the box with just a line is selected, indicating "None." Click the second box, which shows a line with several dots on it.

Instantly, your line graph will update to show markers at every data point. You can adjust the color, opacity, and other settings right within this menu, but the color of the line and the dots will be the same. This method is incredibly fast if you just need a standard line graph with dots.

Pro Tips for Customizing Your Plot Points

Once you've added your markers, you can enhance them to communicate even more information.

• Dynamic Sizing: You can make the size of each dot correspond to another measure. Using the dual axis method, simply drag another measure (like Profit or Quantity) onto the Size tile on the circle marks card. Now, larger dots will represent higher profit or quantity for that month.
• Conditional Coloring: Want to highlight specific months? Create a calculated field, such as IF SUM([Sales]) > 100000 THEN "High" ELSE "Low" END. Drag this new field onto the Color tile on the circle marks card to automatically color-code the dots based on performance.
• Adding Labels: To show the exact value of each point, drag the Sales onto the Label tile on the circle marks card. This will display the sales amount directly on the chart, which is great for presentations.

Final Thoughts

Adding dots to your line graphs in Tableau is a simple adjustment that significantly improves clarity and visual storytelling. Whether you opt for the highly flexible dual axis method to customize every detail or the super-fast built-in marker setting for quick analysis, you now have the skills to make your trendlines more informative and impactful.

While mastering these techniques in Tableau is a great skill, sometimes you need insights without spending time clicking through menus and settings. At Graphed, we designed a tool that allows you to get beautiful reports by just describing what you need. You can simply connect your data and ask, "Show me monthly sales as a line chart with dots for last year," and our AI analyst instantly creates the real-time visualization for you - no manual configuration required.