Pie and doughnut charts in Excel - Deep Dive

Overview - Pie and doughnut charts

What is it?

Pie and doughnut charts are visual tools in Excel that show how parts make up a whole. A pie chart displays data as slices of a circle, where each slice's size matches its value. A doughnut chart is similar but has a hole in the center, making it look like a ring. Both help you quickly see proportions and compare categories visually.

Why it matters

These charts make numbers easier to understand by turning them into pictures. Without them, you would have to read many numbers and guess their relationships. Pie and doughnut charts help in presentations, reports, and decision-making by showing clear, simple comparisons of parts to a total. They save time and reduce confusion.

Where it fits

Before learning pie and doughnut charts, you should know how to enter and organize data in Excel tables. After mastering these charts, you can explore other chart types like bar, line, and combo charts to visualize data in different ways.

Mental Model

Core Idea

Pie and doughnut charts slice a circle to show how each part contributes to the whole.

Think of it like...

Imagine cutting a pizza into slices where each slice size shows how hungry each friend is; the bigger the slice, the hungrier the friend.

Pie Chart Example:

  _________
 /         \
|   Slice  |
|  Sizes   |
 \_________/

Doughnut Chart Example:

  _________
 /         \
|  Ring     |
|  with     |
|  Hole     |
 \_________/

Build-Up - 7 Steps

1

Foundation

Understanding Pie Chart Basics

Concept: Learn what a pie chart is and how it represents data as slices of a circle.

A pie chart divides a circle into slices. Each slice size matches the value it represents compared to the total. For example, if you have sales data for 3 products, the pie chart shows each product's share of total sales as a slice.

Result

You see a circle divided into slices where bigger slices mean bigger values.

Knowing that pie charts show parts of a whole helps you understand when to use them for comparing proportions.

2

Foundation

Creating a Pie Chart in Excel

Concept: Learn how to select data and insert a pie chart in Excel.

Select your data range including labels and values. Then go to Insert > Charts > Pie Chart. Excel creates a pie chart automatically showing your data as slices.

Result

A pie chart appears on your sheet representing your selected data visually.

Understanding the simple steps to create a pie chart empowers you to visualize data quickly.

3

Intermediate

Exploring Doughnut Chart Differences

Concept: Learn how doughnut charts differ from pie charts and when to use them.

A doughnut chart looks like a pie chart but has a hole in the center. This hole can hold labels or other info. Doughnut charts can also show multiple data series as rings, unlike pie charts which show only one series.

Result

You get a ring-shaped chart that can display more complex data than a pie chart.

Knowing doughnut charts can show multiple data sets helps you choose the right chart for layered comparisons.

4

Intermediate

Customizing Chart Appearance

Concept: Learn how to change colors, labels, and styles to make charts clearer.

You can click on chart slices to change colors, add data labels to show values or percentages, and use chart styles for better looks. Adding labels helps viewers understand what each slice means without guessing.

Result

Your chart becomes easier to read and visually appealing.

Customizing charts improves communication by making data clearer and more attractive.

5

Intermediate

Using Data Labels Effectively

🤔Before reading on: do you think showing raw numbers or percentages is better for data labels? Commit to your answer.

Concept: Learn how to add and format data labels to show percentages or values on slices.

Right-click a slice and choose 'Add Data Labels'. Then format labels to show percentages, values, or both. Percentages help compare parts easily, while values show exact numbers.

Result

Labels appear on slices showing clear information about each part.

Choosing the right label format helps viewers grasp the meaning of slices quickly and accurately.

6

Advanced

Handling Small Slices and Data Overlap

🤔Before reading on: do you think very small slices should be shown as is or combined? Commit to your answer.

Concept: Learn how to manage tiny slices that clutter the chart or are hard to see.

Tiny slices can be hard to read or overlap labels. You can pull slices out (explode), combine small slices into an 'Other' category, or use legends and callouts to clarify. Excel also allows adjusting label positions.

Result

Your chart remains clear and readable even with many small categories.

Managing small slices prevents confusion and keeps charts effective for communication.

7

Expert

Advanced Doughnut Chart Uses and Limitations

🤔Before reading on: do you think doughnut charts can effectively show more than two data series? Commit to your answer.

Concept: Explore how doughnut charts can show multiple rings but also their limits in clarity and interpretation.

Doughnut charts can display multiple data series as concentric rings. However, too many rings make the chart hard to read. Experts balance data complexity with clarity by limiting rings and using complementary charts. Also, doughnut charts do not show exact values well, so labels and legends are crucial.

Result

You understand when to use doughnut charts for layered data and when to avoid them.

Knowing doughnut charts' limits helps you avoid confusing visuals and choose better alternatives when needed.

Under the Hood

Excel calculates the total sum of the selected data values. Then it computes each slice's angle by dividing each value by the total and multiplying by 360 degrees. For doughnut charts with multiple series, Excel creates concentric rings, each ring representing one data series. The chart engine draws slices as colored shapes sized by these angles and places labels based on available space.

Why designed this way?

Pie charts have been a simple way to show proportions since early data visualization history. Doughnut charts evolved to add flexibility, like showing multiple series and central labels. Excel's design balances ease of use with visual clarity, avoiding overly complex shapes that confuse users.

Data Values
   ↓
[Sum Calculation]
   ↓
[Calculate Slice Angles]
   ↓
[Draw Pie Slices or Doughnut Rings]
   ↓
[Add Labels and Colors]
   ↓
[Display Chart on Sheet]

Myth Busters - 4 Common Misconceptions

Quick: Do you think pie charts are good for comparing many categories? Commit to yes or no.

Common Belief: Pie charts work well no matter how many categories you have.

Reality: Pie charts become hard to read and interpret when there are many small slices or categories.

Why it matters: Using pie charts with too many categories leads to confusing visuals and misinterpretation of data.

Quick: Do you think doughnut charts show exact values better than pie charts? Commit to yes or no.

Common Belief: Doughnut charts always show data more clearly than pie charts.

Reality: Doughnut charts can be harder to read because the hole reduces slice size, and multiple rings can confuse viewers.

Why it matters: Misusing doughnut charts can make data less clear, hurting communication and decisions.

Quick: Do you think the order of slices in a pie chart does not affect understanding? Commit to yes or no.

Common Belief: Slice order in pie charts doesn't matter for interpretation.

Reality: Slice order affects how viewers perceive data; placing the largest slice first or at the top improves clarity.

Why it matters: Ignoring slice order can reduce chart effectiveness and mislead viewers.

Quick: Do you think pie charts can show negative or zero values? Commit to yes or no.

Common Belief: Pie charts can display negative or zero values just like positive ones.

Reality: Pie charts cannot represent negative or zero values because slices represent parts of a whole and must be positive.

Why it matters: Trying to use pie charts with negative or zero values leads to errors or misleading charts.

Expert Zone

1

The human eye struggles to compare slice sizes accurately, so adding data labels or using bar charts can improve comprehension.

2

Doughnut charts with multiple rings require careful color and label management to avoid confusion between series.

3

Excel's default slice order is based on data order, but manually sorting data can improve chart storytelling.

When NOT to use

Avoid pie and doughnut charts when you have many categories, negative values, or need to show trends over time. Use bar charts, stacked bar charts, or line charts instead for clearer comparisons and trends.

Production Patterns

Professionals use pie charts for simple part-to-whole comparisons in dashboards and reports. Doughnut charts appear in layered data presentations, often with interactive labels or tooltips. Experts combine these charts with filters and slicers to let users explore data dynamically.

Connections

Bar Charts

Alternative visualization for comparing parts

Knowing bar charts helps when pie charts become cluttered or unclear, as bars show exact values and are easier to compare.

Data Storytelling

Visual tool to support narrative

Understanding how pie and doughnut charts highlight proportions aids in crafting clear stories that emphasize key data points.

Human Visual Perception

Limits of how we interpret shapes and sizes

Knowing that humans find it hard to compare angles precisely explains why pie charts can mislead and why labels or alternative charts help.

Common Pitfalls

#1 Using pie charts with too many categories causing clutter.

Wrong approach:

Creating a pie chart with 15+ slices representing many small values.

Correct approach:

Group small categories into 'Other' or use a bar chart for many categories.

Root cause:

Misunderstanding that pie charts are best for few, distinct parts.

#2 Not adding data labels, leaving viewers guessing slice values.

Wrong approach:

Inserting a pie chart without enabling data labels or percentages.

Correct approach:

Add data labels showing percentages or values for clarity.

Root cause:

Assuming the visual alone is enough for understanding.

#3 Trying to use pie charts with negative or zero values.

Wrong approach:

Selecting data with negative numbers and inserting a pie chart.

Correct approach:

Use bar or line charts for data with negative or zero values.

Root cause:

Not knowing pie charts require positive parts of a whole.

Key Takeaways

Pie and doughnut charts visually show how parts make up a whole using slices of a circle.

They are best for comparing a few categories with positive values to highlight proportions clearly.

Customizing colors, labels, and slice order improves chart clarity and communication.

Doughnut charts can show multiple data series but can become confusing if overused.

Knowing when to use or avoid these charts helps you present data effectively and avoid misleading visuals.