How to Create a 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. on this page, we’ll go over what a pie chart is, how to create a pie chart and use it along with examples. Let’s get started!
 

Table of Contents

• What is a Pie Chart?
• Pie Chart Definition
• How to Create a Pie Chart
• Pie Chart Formula
• How to Read a Pie Chart
• Pie Chart Examples
• Conclusion

 

What is a Pie Chart?

The term "pie chart" comes from its similarity to a sliced pie. It is a chart that helps us quickly illustrate how each category contributes to the whole. It is commonly used in statistics, business, education, and media to present percentages and comparisons in a straightforward visual format. For example, we can show the student’s activities like playing, studying, sleeping, etc throughout the day using a pie chart diagram.

Representation of student’s activities through a pie chart:

Definition of 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. To determine the size of each slice in the pie chart we need to know the angle that it forms at the center of the pie chart. Here is the formula used to calculate the angle of each slice in pie chart: 

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.

How to Create a Pie Chart

Here’s is a step-by-step process of creating a pie chart:

Step 1: First, list each data category and their respective values.  
For example: Let's create a pie chart for a student daily activities like studies, sleeping, playing, etc. for a day:  

Time spent for studying = 4 hours  
Time for sleeping = 8 hours  
Time for playing = 6 hours  
Others = 6 hours  

Step 2: Add up all the values: 
Now, we need to check the total time = 4 + 8 + 6 + 6 = 24 hours  

Step 3: Calculate the percentage of each category:

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 using given formula.  
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.

 

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.

 

Pie Chart 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!

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