Treemap in Power BI - Cell-by-Cell Formula Trace

Sample Data

Sales data by Category and Subcategory with sales amounts.

Cell	Value
A1	Category
B1	Subcategory
C1	Sales
A2	Fruits
B2	Apples
C2	100
A3	Fruits
B3	Bananas
C3	150
A4	Vegetables
B4	Carrots
C4	80
A5	Vegetables
B5	Broccoli
C5	120

Formula Trace

SUM(Sales) by Category and Subcategory for Treemap size

Step 1: Group data by Category and Subcategory

Step 2: Calculate sum of Sales for each group

Step 3: Calculate total sales for each Category

Step 4: Assign rectangle sizes proportional to sales sums

Cell Reference Map

    A          B          C
1 |Category |Subcategory| Sales |
2 | Fruits  | Apples    |  100  |
3 | Fruits  | Bananas   |  150  |
4 |Vegetables| Carrots  |  80   |
5 |Vegetables| Broccoli |  120  |

The treemap uses Category (A), Subcategory (B), and Sales (C) columns to group and size rectangles.

Result

Treemap Visualization:
+-----------------------------+
| Fruits (250)                |
|  +-----------+------------+ |
|  | Apples(100)| Bananas(150)| |
+-----------------------------+
| Vegetables (200)            |
|  +----------+-------------+ |
|  | Carrots(80)| Broccoli(120)| |
+-----------------------------+

The treemap shows two main rectangles for Fruits and Vegetables sized by total sales. Inside each, smaller rectangles represent subcategories sized by their sales.

Sheet Trace Quiz - 3 Questions

What determines the size of each rectangle in the treemap?

A The number of subcategories only

B The alphabetical order of Categories

C The sum of Sales for each Category and Subcategory

D The average sales per subcategory

Key Result

Treemap groups data by category fields and sizes rectangles by sum of a numeric measure.

Practice

1. What is the main purpose of a Treemap visualization in Power BI?

easy

A. To list data in rows and columns

B. To display data as a line over time

C. To show parts of a whole using size and color

D. To create a map with geographic locations

Solution

1. Step 1: Understand Treemap visualization

   A Treemap shows data as nested rectangles where size and color represent values.

2. Step 2: Compare options to definition

   Only To show parts of a whole using size and color describes showing parts of a whole using size and color, which matches Treemap.

3. Final Answer:

   To show parts of a whole using size and color -> Option C

4. Quick Check:

   Treemap = parts of whole with size and color [OK]

Hint: Treemap = parts of whole shown by size and color [OK]

Common Mistakes:

• Confusing Treemap with line chart
• Thinking Treemap is a table
• Mixing Treemap with map visual

2. Which fields should you add to a Treemap visual in Power BI to show category sizes correctly?

easy

A. Add 'Group' to Tooltip and 'Values' to Axis

B. Add 'Group' to Values and 'Values' to Legend

C. Add 'Values' to Group and 'Group' to Values

D. Add 'Group' to Group and 'Values' to Values

Solution

1. Step 1: Recall Treemap field roles

   Treemap uses 'Group' for categories and 'Values' for size of rectangles.

2. Step 2: Match fields to correct roles

   Add 'Group' to Group and 'Values' to Values correctly assigns 'Group' to Group and 'Values' to Values, which is required.

3. Final Answer:

   Add 'Group' to Group and 'Values' to Values -> Option D

4. Quick Check:

   Group = Group, Values = Values [OK]

Hint: Group goes to Group, Values goes to Values in Treemap [OK]

Common Mistakes:

• Swapping Group and Values fields
• Putting Values in Legend or Axis incorrectly
• Using Tooltip instead of Group or Values

3. Given a dataset with categories and sales amounts, what will a Treemap show if one category has sales 500 and another 1000?

medium

A. The category with 1000 sales will have a rectangle twice as large as the 500 sales category

B. Both categories will have rectangles of the same size

C. The category with 500 sales will have a rectangle twice as large as the 1000 sales category

D. The Treemap will only show color differences, not size

Solution

1. Step 1: Understand Treemap size representation

   Treemap rectangle size is proportional to the value it represents.

2. Step 2: Compare sales values

   1000 is twice 500, so the rectangle for 1000 sales will be twice as large as for 500 sales.

3. Final Answer:

   The category with 1000 sales will have a rectangle twice as large as the 500 sales category -> Option A

4. Quick Check:

   Size ∝ Value, so 1000 sales rectangle is twice 500 sales [OK]

Hint: Rectangle size matches value proportionally in Treemap [OK]

Common Mistakes:

• Thinking smaller value has bigger rectangle
• Assuming rectangles are same size
• Believing Treemap uses only color, not size

4. You created a Treemap but all rectangles appear the same size despite different values. What is the most likely cause?

medium

A. You added the 'Group' field to Values instead of 'Values'

B. You used a stacked bar chart instead of Treemap

C. You forgot to add any fields to the visual

D. You added 'Values' to Group and 'Group' to Values

Solution

1. Step 1: Analyze field placement impact

   Adding 'Group' to Values means Power BI treats categories as numeric values, causing equal sizes.

2. Step 2: Identify correct field usage

   Values field must be numeric data for size; Group is categorical and should not be in Values.

3. Final Answer:

   You added the 'Group' field to Values instead of 'Values' -> Option A

4. Quick Check:

   Wrong field in Values causes equal rectangle sizes [OK]

Hint: Ensure numeric field is in Values, not Group [OK]

Common Mistakes:

• Swapping Group and Values fields
• Using wrong visual type
• Leaving fields empty

5. You want to create a Treemap showing sales by product category and highlight categories with sales above 1000 in a different color. How can you achieve this in Power BI?

hard

A. Add 'Sales' to Group and 'Group' to Values, then filter categories with sales > 1000

B. Add 'Group' to Group, 'Sales' to Values, and create a measure with conditional color formatting based on sales > 1000

C. Use a stacked bar chart instead and apply color rules

D. Add 'Group' to Tooltip and 'Sales' to Legend without conditional formatting

Solution

1. Step 1: Set up Treemap fields correctly

   Add 'Group' to Group for categories and 'Sales' to Values for size representation.

2. Step 2: Apply conditional color formatting

   Create a measure that returns different colors based on sales > 1000, then use it in color formatting.

3. Final Answer:

   Add 'Group' to Group, 'Sales' to Values, and create a measure with conditional color formatting based on sales > 1000 -> Option B

4. Quick Check:

   Correct fields + conditional color measure = desired Treemap [OK]

Hint: Use conditional color measure with correct fields in Treemap [OK]

Common Mistakes:

• Swapping Group and Values fields
• Not using conditional formatting for color
• Choosing wrong visual type