Tableau Scatter Plots and Bubble Charts

Scatter plots reveal relationships between two numeric measures. Bubble charts add a third measure using circle size. Both charts help you spot outliers, clusters, and correlations that bar charts and line charts miss entirely.

What a Scatter Plot Shows

A scatter plot places two measures on two axes. Each dot represents one data point — a customer, a product, a transaction. The position of each dot answers two questions at once: What is its value on the X axis? What is its value on the Y axis?

Business Analogy

Question: Do products with high sales also have high profit?

Scatter Plot — X Axis: Sales  |  Y Axis: Profit
                    ^
         Profit     |               *  *
                    |          *  *
                    |       * *
                    |   *  *
                    | *
                    +------------------------------> Sales
                    Low                      High

Pattern: Points cluster from bottom-left to top-right
→ Higher sales tend to mean higher profit (positive correlation)

Building a Scatter Plot

1. Drag a Measure (e.g., Sales) to Columns — this becomes the X axis
2. Drag a second Measure (e.g., Profit) to Rows — this becomes the Y axis
3. Tableau draws one single dot (the aggregate of all data)
4. Drag a Dimension (e.g., Product Name) to Detail in the Marks Card
5. Now each product becomes its own dot on the scatter plot

Why Step 4 Matters

Without a Dimension in Detail, Tableau shows one aggregated dot. Adding a Dimension to Detail tells Tableau to disaggregate — to draw one dot per unique value in that Dimension. The more granular the Dimension (Product Name vs Category), the more dots appear.

Identifying Outliers

Outliers appear far from the main cluster of dots. A product with very high sales but negative profit appears in the top-left area of a Sales vs Profit scatter — far from the general diagonal pattern. Click any outlier dot to see its details in the tooltip.

Diagram: Outlier Detection

     Profit
       ^
       |         * * *       Normal products (upper right)
       |     * *   *
       |   *  *
       |  *
       | * *
       |
  -----+----------------------------------------> Sales
       |
  LOSS | *                  ← Outlier: High sales, negative profit
       |                      (This product needs investigation)

Adding Color to a Scatter Plot

Drag a Dimension to the Color box in the Marks Card. Each dot gets a color based on its category value. For example, dragging Product Category colors dots as Furniture, Technology, or Office Supplies. A color legend appears automatically. You can now see whether high-loss outliers cluster in one category.

Bubble Charts

A bubble chart is a scatter plot where each dot has a different size. The size encodes a third Measure. Drag a third Measure to the Size box in the Marks Card. Dots grow or shrink based on that value — bigger bubble means more of that measure.

Three-Measure Bubble Chart

X Axis: Sales
Y Axis: Profit
Bubble Size: Number of Orders

   Profit
     ^
     |      O          Large O = many orders
     |   o      O      Small o = few orders
     |       o
     |  o
     +-----------------------> Sales

A large bubble far upper-right = high sales, high profit, many orders
  → This is your best product
A large bubble in the loss zone = many orders but losing money
  → This product needs repricing

Adding Labels to Bubbles

Drag the Dimension you used for Detail to the Label box in the Marks Card. Each bubble now shows the name of the product, customer, or category it represents. For crowded scatter plots, turn labels on only for marks above a threshold using the label settings to show "Min/Max" only.

Trend Lines on Scatter Plots

Open the Analytics Pane and drag "Trend Line" onto the scatter plot. Tableau draws a best-fit line through all the dots. The slope shows the direction of the relationship. A steeper upward slope means a stronger positive correlation between the two measures.

Trend Line Interpretation

Reference Bands

Drag "Reference Band" from the Analytics Pane onto the scatter plot. Set it between two values — for example, zero and the average. This shades a region of the chart, making it visually clear which dots fall above and below a threshold. The shaded zone is often called the "danger zone" in business reviews.

When to Use Scatter vs Bubble vs Bar

Summary

Scatter plots place two measures on two axes and one dot per data point reveals patterns, correlations, and outliers. Bubble charts add a third measure through dot size. Dragging a Dimension to Color, Size, or Label layers additional meaning onto each dot. Trend lines show the direction and strength of the relationship. These charts excel at spotting what other chart types hide — products losing money despite high sales, customers buying frequently but returning often, or regions growing fast but remaining unprofitable.