Pie Chart

A pie chart is a popular way to show data visually. Whether you're looking at business reports, student grades, or survey responses, pie charts make it easy to see how parts relate to the whole. Each slice of the pie represents a portion of the total, which is really helpful for understanding data quickly. 

In this guide, we’ll go over what a pie chart is, how to use it, how to make one, and much more. Let’s get started!

 

Table of Contents

• What is a Pie Chart?
• Pie Chart Percentage Formula
• How to Read a Pie Chart
• How to Make a Pie Chart
• Advantages and Disadvantages of Pie Chart
• Misconceptions
• Real-Life Applications
• Solved Examples
• Conclusion
• FAQs on Pie Chart

 

What is a Pie Chart?

A pie chart, also called a circle chart, is a circular graph divided into slices that show proportions. Each slice represents a portion of the total, and together, all slices add up to 100% of the data. Larger slices indicate larger values, while smaller slices represent smaller values.

Meaning and Definition of Pie Chart  
The term "pie chart" comes from its similarity to a sliced pie. It is commonly used in statistics, business, education, and media to present percentages and comparisons in a straightforward visual format. A pie chart helps quickly illustrate how each category contributes to the whole.

Formula of Pie Chart  
To calculate the angle of each slice in a pie chart:

Angle of Slice = (Category Value ÷ Total Value) × 360°

This formula turns numerical data into circular segments, making it easy to see proportions.

 

Pie Chart Percentage Formula

Formulas:

• Percentage = (Individual Value ÷ Total Value) × 100

• Angle = (Individual Value ÷ Total Value) × 360°

Example:
A class has 40 students: 15 like Math, 10 like Science, 15 like English.

Step 1: Total Students
Total = 40

Step 2: Percentage

• Math: (15 ÷ 40) × 100 = 37.5%

• Science: (10 ÷ 40) × 100 = 25%

• English: (15 ÷ 40) × 100 = 37.5%

Step 3: Angle

• Math: (15 ÷ 40) × 360° = 135°

• Science: (10 ÷ 40) × 360° = 90°

• English: (15 ÷ 40) × 360° = 135°

Answer:

• Math: 37.5%, 135°

• Science: 25%, 90°

• English: 37.5%, 135°

 

How to Read a Pie Chart

To interpret a pie chart, follow these steps:

• Check the total: The whole pie equals 100%.

• Read the labels: Each slice has a label showing its name, percentage, or value.

• Compare sizes: Bigger slices represent larger amounts.

• Look for legends: Colours or patterns help match slices with data.

Being able to read a pie chart is important in exams, reports, and presentations.

 

How to Make a Pie Chart

Here’s how to create a pie chart step by step with an example:

Step 1: List your data categories and their values.  
Example: A student spends time daily on activities:  

Study = 4 hours  
Sleep = 8 hours  
Play = 6 hours  
Others = 6 hours  

Step 2: Add up all the values.  
Total time = 4 + 8 + 6 + 6 = 24 hours  

Step 3: Calculate each category's percentage.  

Study = (4 ÷ 24) × 100 = 16.7%  
Sleep = (8 ÷ 24) × 100 = 33.3%  
Play = (6 ÷ 24) × 100 = 25%  
Others = (6 ÷ 24) × 100 = 25%  

Step 4: Turn each percentage into an angle.  
Formula: (Percentage × 360°) ÷ 100  

Study = (16.7 × 360) ÷ 100 ≈ 60°  
Sleep = (33.3 × 360) ÷ 100 ≈ 120°  
Play = (25 × 360) ÷ 100 = 90°  
Others = (25 × 360) ÷ 100 = 90°  

Step 5: Draw a circle and divide it into slices.  

Use a protractor to mark 60°, 120°, 90°, and 90°.  

Each slice represents one category.  

Step 6: Label each slice.  
Write "Study – 16.7%", "Sleep – 33.3%", "Play – 25%", and "Others – 25%".  

Final Result: A pie chart that clearly shows how a student spends their 24 hours in a day.

 

Advantages and Disadvantages of Pie Chart

Here are some pros and cons of using pie charts:

Advantages:

•  They’re simple and visually appealing.

•  Easy to compare parts of the whole.

•  Great for showing percentage data.

Disadvantages:

•  Not ideal for large datasets or detailed comparisons.

•  It can be confusing if slices are similar in size.

•  Hard to read without exact numbers.

 

 

Misconceptions

Let’s clear up some common myths about pie charts:

• Myth 1: Pie charts can show multiple variables.

Reality: They work best for a single variable.

• Myth 2: Pie charts are clear without numbers.

Reality: Labels and percentages are needed for accuracy.

• Myth 3: All slices should be the same size.

Reality: Sizes vary according to values.

• Myth 4: Pie charts are always better than bar charts.

Reality: Bar charts are often easier for detailed comparisons.

• Myth 5: You can use pie charts for any data.

Reality: They work for categorical data, not continuous data.

 

Real-Life Applications

Here are some fun facts and ways pie charts are used:

• Business Analytics: Companies use them to show market share in presentations.

• Student Performance: Teachers can visualise test scores this way.

• Election Results: Good for showing how votes are split up.

• Budget Tracking: Helpful for personal finance to show spending.

• Food Labels: Nutrition breakdowns often use pie charts.

 

Solved Examples

Example 1: Creating a Pie Chart

Question: A student spends 4 hours studying, 2 hours on sports, and 6 hours sleeping. Draw a pie chart.

Solution: Total time = 12 hours. 

Study angle = (4/12) × 360 = 120°

Sports angle = (2/12) × 360 = 60° 

Sleep angle = (6/12) × 360 = 180°.

Draw the pie and label each slice.

 

Example 2: Percentage Conversion

Question: If the Food slice in a pie chart is 90°, what percentage is that?

Solution: (90/360) × 100 = 25%.

So, Food is 25% of the total.

 

Example 3: Reading a Pie Chart

Question: In a survey, 50% chose chocolate, 30% chose vanilla, and 20% chose strawberry. Which flavour is the most popular?

Solution: Chocolate (50%) has the largest slice.

 

Example 4: Angle for Given Value

Question: If 40 out of 100 people like tea, what angle does that represent?

Solution: (40/100) × 360 = 144°.

So, tea takes up 144°.

 

Example 5: Class Performance Pie Chart

Question: A class has 25 A grades, 15 B grades, and 10 C grades. Draw pie chart sectors.

Solution: = 50.

   A: (25/50) × 360 = 180°.

   B: (15/50) × 360 = 108°.

   C: (10/50) × 360 = 72°.

 

Conclusion

Pie charts are a straightforward way to visualise data parts. This guide gives you all the info on pie charts, from their definitions to how to create and read them. Whether you're a student, teacher, or analyst, knowing how to work with pie charts can turn data into useful insights. Now that you’ve got the hang of it, start making your pie charts and let the data tell its story!

 

Frequently Asked Questions on Pie Chart

1. What is the entire clarification of a pie chart?

Answer: A pie chart is a round graph divided into slices to symbolise the relative proportions of different classes within an entire.

 

2. What are the rules for pie charts?
 

Answer: The main rule for pie charts is that all slices must total 100% or 360° of the circle.

 

3. What is known as a pie graph?

Answer: A pie graph is every other call for a type of chart, used to visually represent records elements of an entire.

 

4. What are the 4 varieties of pie charts?

Answer: Standard pie chart, 3D pie chart, exploded pie chart, and doughnut chart.

 

Learn how to represent data visually and effectively with pie charts at Orchids The International School!