Pie and donut charts in Power BI - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the main purpose of a pie chart?

A pie chart shows how parts make up a whole by dividing a circle into slices. Each slice represents a category's proportion.

beginner

How does a donut chart differ from a pie chart?

A donut chart is like a pie chart but with a hole in the center. This hole can be used to display extra information or make the chart easier to read.

beginner

Why should you avoid using too many slices in a pie or donut chart?

Too many slices make the chart hard to read and compare. It's better to group smaller categories into an 'Other' slice for clarity.

beginner

What is a good real-life example to explain pie charts?

Imagine a pizza cut into slices where each slice shows how many friends like a certain topping. The whole pizza is all friends combined.

beginner

In Power BI, how do you create a donut chart?

Select your data, then choose the donut chart icon from the Visualizations pane. Drag the category field to 'Legend' and the value field to 'Values'.

What does each slice in a pie chart represent?

A A separate dataset

B A part of the whole

C A timeline event

D A data filter

Each slice shows a part of the total, helping you see proportions.

What is the main visual difference between a pie chart and a donut chart?

A Donut charts use 3D effects

B Pie charts have bars

C Donut charts have a hole in the center

D Pie charts show trends over time

Donut charts look like pies with a hole in the middle.

Why should you limit the number of slices in a pie chart?

A Too many slices make it hard to read

B Power BI does not allow more than 5 slices

C More slices slow down the computer

D Slices must be equal size

Too many slices clutter the chart and confuse viewers.

In Power BI, where do you drag the category field to create a pie chart?

A Filters

B Values

C Tooltips

D Legend

The category field goes to Legend to define slices.

Which scenario is best for using a donut chart?

A Showing parts of a whole with extra info in the center

B Displaying time series data

C Comparing two unrelated datasets

D Showing detailed text data

Donut charts show parts of a whole and can display info in the center hole.

Explain how pie and donut charts help visualize data and when to use each.

Think about how a pizza slice shows part of the whole pizza.

Describe the steps to create a donut chart in Power BI and best practices for its use.

Remember the Visualizations pane and dragging fields.

Practice

1. What is the main purpose of a pie chart in Power BI?

easy

A. To list data in rows and columns

B. To show parts of a whole as slices of a circle

C. To compare two numerical values side by side

D. To display trends over time with lines

Solution

1. Step 1: Understand pie chart basics

   A pie chart divides a circle into slices representing parts of a whole.

2. Step 2: Compare with other chart types

   Line charts show trends, bar charts compare values, tables list data. Only pie charts show parts of a whole as slices.

3. Final Answer:

   To show parts of a whole as slices of a circle -> Option B

4. Quick Check:

   Pie chart = parts of whole [OK]

Hint: Pie charts always show parts of a whole circle [OK]

Common Mistakes:

• Confusing pie charts with line charts
• Thinking pie charts show trends over time
• Using pie charts for detailed data tables

2. Which of the following is the correct way to add a donut chart in Power BI?

easy

A. Select the donut chart icon from the Visualizations pane

B. Write a DAX formula to create a donut chart

C. Use the Data view to draw a donut chart manually

D. Insert a pie chart and then change its color to white

Solution

1. Step 1: Identify how to add visuals in Power BI

   Power BI provides a Visualizations pane with icons for different charts.

2. Step 2: Find the donut chart icon

   The donut chart icon is available to select directly; no DAX or manual drawing is needed.

3. Final Answer:

   Select the donut chart icon from the Visualizations pane -> Option A

4. Quick Check:

   Donut chart = Visualizations pane icon [OK]

Hint: Use the Visualizations pane icons to add charts [OK]

Common Mistakes:

• Trying to create charts with DAX formulas
• Using Data view to draw charts manually
• Changing colors to fake chart types

3. Given a dataset with categories and sales, what will a donut chart show if you drag 'Category' to Legend and 'Sales' to Values?

medium

A. A bar chart comparing sales amounts

B. A line showing sales trend over categories

C. A table listing sales by category

D. Slices representing sales share of each category

Solution

1. Step 1: Understand donut chart data fields

   Legend defines slices (categories), Values define slice sizes (sales amounts).

2. Step 2: Interpret the visual output

   The donut chart will show slices sized by sales share per category, not trends or tables.

3. Final Answer:

   Slices representing sales share of each category -> Option D

4. Quick Check:

   Legend + Values = slices sized by values [OK]

Hint: Legend = slices, Values = slice size in pie/donut charts [OK]

Common Mistakes:

• Expecting a line or bar chart from a donut chart
• Confusing legend with axis in charts
• Thinking donut charts show raw numbers, not shares

4. You created a donut chart but it shows only one slice instead of multiple categories. What is the likely cause?

medium

A. The 'Category' field was not added to the Legend well

B. The 'Sales' field is empty or zero for all categories

C. The donut chart does not support multiple slices

D. The data model has no relationships

Solution

1. Step 1: Check the Legend field in the donut chart

   If 'Category' is missing or not properly added to Legend, the chart shows one slice.

2. Step 2: Verify other options

   Empty sales would show no slices, donut charts support multiple slices, and relationships affect filtering but not basic slices.

3. Final Answer:

   The 'Category' field was not added to the Legend well -> Option A

4. Quick Check:

   Legend missing = one slice [OK]

Hint: Always add categories to Legend for multiple slices [OK]

Common Mistakes:

• Assuming donut charts can't show multiple slices
• Ignoring the Legend field placement
• Blaming data model relationships for slice count

5. You want to show total sales in the center of a donut chart along with category slices. Which feature should you use in Power BI?

hard

A. Use the donut chart's center text option to display total sales

B. Enable the 'Detail labels' and set 'Label style' to 'Data value and percentage'

C. Add a card visual on top of the donut chart manually

D. Create a measure that sums sales and add it to Legend

Solution

1. Step 1: Understand donut chart limitations

   Built-in donut charts do not have a direct center text option for totals with multiple category slices; the center category label works only for single categories.

2. Step 2: Apply best practice workaround

   Create a total sales measure, add a Card visual to display it, and manually position the card in the donut's center hole. Other options fail: no center text (A), labels on slices (C), legend misuse (D).

3. Final Answer:

   Add a card visual on top of the donut chart manually -> Option C

4. Quick Check:

   Card overlay = donut center total [OK]

Hint: Overlay Card visual in donut center for totals [OK]

Common Mistakes:

• Believing donut charts have native center text for totals
• Adding totals to Legend field
• Using detail labels expecting center display