Treemap in Power BI - Step-by-Step Guide

Introduction

A treemap shows data as nested rectangles. It helps you see parts of a whole and compare sizes easily. This is useful when you want to visualize categories and their values in a compact space.

When you want to show sales by product category and subcategory in one view.

When you need to compare market share of different companies visually.

When you want to display budget allocation across departments and teams.

When you want to spot the largest and smallest segments in your data quickly.

When you want a colorful, space-efficient way to show hierarchical data.

Steps

Step 1: Click

- Report view pane

The report canvas is active and ready for visuals

Step 2: Select

- Visualizations pane > Treemap icon

A blank treemap visual appears on the canvas

Step 3: Drag

- Fields pane > Category field

The treemap shows rectangles sized by category

Step 4: Drag

- Fields pane > Values field

The size of each rectangle adjusts to the value amount

Step 5: Drag

- Fields pane > Details field (optional)

The treemap breaks down categories into sub-rectangles

Step 6: Click

- Format pane > Data colors

You can customize colors for each category

Step 7: Click

- Format pane > Labels

You can turn on/off and format labels inside rectangles

Before vs After

Before

Report canvas is empty with no visuals

After

Treemap visual shows colored rectangles sized by sales amount for each product category

Settings Reference

Data colors

📍 Format pane > Data colors

Change the colors of the rectangles to improve clarity or match branding

Default: Default palette

Category labels

📍 Format pane > Labels

Show or hide category names inside the rectangles

Default: On

Detail labels

📍 Format pane > Labels

Show or hide subcategory names inside smaller rectangles

Default: On

Tooltip

📍 Format pane > Tooltip

Show details when hovering over rectangles

Default: On

Common Mistakes

Not adding a value field to the treemap

Without a value, the treemap cannot size rectangles properly and may show equal sizes

Always drag a numeric field (like sales or count) to the Values area

Using too many categories or details

Too many small rectangles make the treemap cluttered and hard to read

Limit categories or use filters to keep the treemap clear and meaningful

Summary

Treemaps display data as nested rectangles sized by values.

They help compare parts of a whole visually and spot big or small segments.

Remember to add a value field and keep categories manageable for clarity.