What is a Pie Diagram?

A pie chart is a type of graph used to represent data. It is a type of pictorial representation of data. It requires a list of categorical variables and numerical variables. In the term pie chart, pie represents a whole and the slices in the pie chart represent the parts of a whole.


A pie diagram is also known as a circle chart. It divides the statistical data into slices or sectors. Each sector in a pie diagram represents a proportionate part of the whole. Pie diagrams work best in order to find the composition of something. Pie diagrams also replace other graphs such as bar graphs, line graphs, line plots, histograms, etc.


Pie Diagram Formula

The pie chart is considered as one of the important types of data representation. It contains different sectors and segments also called pie in a pie chart. Each segment or sector forms a certain portion of the total percentage. The total of all is equal to 360 degrees. The total value of the pie is always 100%.


To get the pie diagram formula, the following steps are to be considered:

  1. Collect and categorize the information into meaningful data.

  2. From the data collected, calculate the total.

  3. Divide the categories according to the heads.

  4. Convert those numbers to percentages.

  5. The last step is to convert the percentages to degrees.

The pie diagram formula is given as = ( given data / total value of data ) x 360.


Pie Chart Definition: A type of graph in which a circle is divided into sectors that represent a proportion of the whole.


Practical Implication of Pie Chart

The pie chart is extensively used because of its ease in data readability and access to information. It is the simplest form as data are easily compared in a pie chart. Some of the pie diagram examples in real life are as follows:

  1. In a  business, it is used to compare the growth areas such as business profits, turnover, exposure, etc.

  2. It is also used to represent categorical data.

  3. Pie charts are basically used for comparing data.

  4. In schools, pie charts may be used to show how much time is allotted for each section.

  5. Used to measure the relative size of data such as type of house people have, type of 2 wheelers or 4 wheelers people own.

  6. The number of customers arriving in the retail market on weekends.

  7. Types of food and beverages liked by people in a restaurant.

  8. Representation of mobile brands in the market.

  9. Comparison of sales of different brands.

Advantages of Using Pie Diagrams

As already discussed, pie charts are considered a convenient graphical representation because of their ease of understanding data at one glance. This is possible as the pie is broken down into sectors representing the portion of the whole. Some of its advantages are listed below:

  1. The data is simple and in an easy to understand form.

  2. Data is represented visually

  3. To add on a few points, we can manipulate pieces of data in the form of sectors in a pie chart.

  4. No underlying numbers are required to read the data, as all information is presented in a pie chart.

  5. It provides a data comparison at a glance. The immediate analysis is possible by just looking at the pictorial presentation of Pie chart.

  6. It is also considered the best communication tool even to the unaware or uninformed readers.

Shortcomings of Using Pie Diagrams

There are two sides to every aspect. Looking at a pie chart presentation also has some of the disadvantages associated with it. A few of them are listed below:

  1. It becomes less effective when too many pieces of information are to be displayed in a pie chart.

  2. When adding on too many pieces of information or making separate labels for each information creates clutter. It is often hard to read those data.

  3. The pie chart only represents one set of information.

  4. To compare multiple sets, a series of data is required.

  5. It makes it difficult for readers when a quick analysis is needed.

FAQs (Frequently Asked Questions)

Q1. Explain the Pie Chart and What is Used to Represent Data in the Pie Chart?

Ans. The pie chart is a simple pictorial representation of data where the sector represents the relative size of data. Different sizes may be used to represent the same data using pie charts. They are used to represent the proportional data. The concept of pie slices is used to show the percentage of particular data in a whole pie chart.


A sector in the pie chart is also known as pie. A pie is used to represent data in a pie chart. To find the total number of pieces in data, we have to multiply the pie percentage by the total number, and then divide it by 100.


For example to find the value of 20% where the total number of data is equal to 150. The value calculated will be 20% of the pie slice.  (20 x 150) / 100 = 30.

Q2. Explain with an Example of How a Pie Chart is Constructed?

Ans. Steps of construction of a pie chart for a given data. A set of rules is followed to construct a pie chart. This is explained in the following manner:

  1. Find the central angle of the pie chart by using the formula given.

  2. Draw a circle of any radius according to the size of the pie chart.

  3. Draw a horizontal radius.

  4. Starting with the horizontal radius draw radii, making angles corresponding to the values of respective categories.

  5. Repeat the same process with all the categories that are to be showcased in a pie chart.

  6. After the allotment of all categories, shade the portion of the pie in different shades so that they are easily distinguishable.

Let us understand the pie chart with a simple example:


(Image will be uploaded soon)


The pie diagram shows sectors of students having a different collection of books. In the diagram:

  • 44% of students like comic books.

  • 19% of students like storybooks.

  • 6% of students are in favour of poem books.

  • The remaining that is 31% of students are in favour of puzzle books.