Pie Chart

Pie-chart illustrates proportions into sectors or slices. Each sector denotes a proportionate part of the whole. If you’re trying to find out the composition of something, Pie-chart works the best at that time.

Pie Chart Value

The total value of the pie is always 100%.

Pie Chart

Pie Chart Example:

Imagine a teacher surveys her class on the basis of their favorite Sports:

Football Hockey Cricket Basketball Badminton
10 5 5 10 10

The data above can be represented by a pie-chart as following and by using the circle graph formula i.e. the pie chart formula given below. It makes the size of portion easy to understand.

Pie Chart Formula

Step 1: First, Enter the data into the table.

Football Hockey Cricket Basketball Badminton
10 5 5 10 10

Step 2: Add all the values in the table to get the total.

I.e Total students are 40 in this case.

Step 3: Next, divide each value by the total and multiply by 100 to get a percent:

Football Hockey Cricket Basketball Badminton
10\(\div\) 40 ✕ 100=25% 5\(\div\) 40 ✕ 100=12.5% 5\(\div\) 40 ✕ 100=12.5% 10\(\div\) 40 ✕ 100=25% 10\(\div\) 40 ✕ 100=25%

Step 4: Next to know how many degrees for each “pie sector” we need, we will take a full circle of 360\(^{\circ}\) and follow the calculations below:

Central angle of each component = (\(\frac{Value\, of\, each \,component}{Sum\, of\,values\, of\, all\,componenents}\)\(\times\)360\(^{\circ}\))

Football Hockey Cricket Basketball Badminton
10\(\div\) 40 ✕ 100=25% 5\(\div\) 40 ✕ 100=12.5% 5\(\div\) 40 ✕ 100=12.5% 10\(\div\) 40 ✕ 100=25% 10\(\div\) 40 ✕ 100=25%
10\(\div\) 40 ✕ 360=90\(^{\circ}\) 5\(\div\) 40 ✕ 360=45\(^{\circ}\) 5\(\div\) 40 ✕ 360=45\(^{\circ}\) 10\(\div\) 40 ✕ 360=90\(^{\circ}\) 10\(\div\) 40 ✕ 360=90\(^{\circ}\)

Now you can draw a pie chart.

Step 5: Draw a circle and use the protractor to measure the degree of each sector.

Tip – You can color each sector and label it. Example of Label is: Football (25%)

Uses of Pie Chart

Within a business, it is used to compare areas of growth such as turnover, profit, and exposure.
To represent categorical data.

Advantages of a Pie Chart

  • The picture is simple and easy-to-understand
  • Data can be represented visually as a fractional part of a whole
  • It helps in providing an effective communication tool for the even uninformed audience
  • Provides a data comparison for the audience at a glance to give an immediate analysis or to quickly understand information
  • No need for readers to examine or measure underlying numbers themselves which can be removed by using this chart
  • To emphasize few points you want to make, you can manipulate pieces of data in the pie chart

Disadvantages of a Pie Chart

  • It becomes less effective, If there are too many pieces of data to use
  • If there are too many pieces of data, and even if you add data labels and numbers may not help here, They themselves may become crowded and hard to read
  • As this chart only represents one data set, You need a series to compare multiple sets
  • This may make it more difficult for readers when it comes to analyze and assimilate information quickly

You can practice another pie chart question for class 8 given below:

Solve on your own: (Practice Question)

Question: Priya lists down her monthly expenditure as follows:

Expenditure Amount
Rent 4000
Food 5400
Clothing 2800
Savings 400

Draw a pie chart for her monthly expenses.

You might also like to practice some more Mathematical topics. Download BYJU’S for a variety of topics and concepts to learn from.


Practise This Question

Suppose a medium pizza was eaten by you and your 7 friends. As you were still hungry, you ordered a large pizza this time. The large pizza is again cut into 8 equal parts. The percentage of full large pizza eaten by you is: