Bar Graph – Definition, Types, Examples, Practice Problems, Facts

What is a Bar Graph?

A bar graph can be defined as a graphical representation of data, quantities, or numbers using bars or strips. They are used to compare and contrast different types of data, frequencies, or other measures of distinct categories of data. For example,

Graph to represent student’s favorite season

The above graph shows how many students like which season. The seasons are listed as spring, summer, fall, or winter on the bottom horizontal axis of the graph. The number of students is written on the vertical axis as 0, 1, 2…

Elements of a Bar Graph

Bars

The rectangles drawn on the bar charts are called “bars”. The bars display the number of items under particular categories.

Axes

There are two axes present on the graph. One axis is used to represent the numerical values whereas the other represents the categorical data against which the numerical data is plotted.

In the same example, 

Graph to represent season’s liked by students of a class

Alt text: Graph to represent season’s liked by students of a class

The seasons on the x-axis represent the categorical data and the number of students on the y-axis represents the numerical possible values. And the blue bars represent the number of students pertaining to each category or season.

Properties of Bar Graph

  • A bar graph is the representation of numerical data by rectangles (or bars) of equal width and varying height. 
  • The gap between one bar and another should be uniform throughout. 
  • It can be either horizontal or vertical. 
  • The height or length of each bar relates directly to its value.

Types of Bar Graph

Horizontal: Here, the bars are drawn horizontally from left to right. The data categories are placed on the vertical axis and numerical values are placed on the graph’s horizontal axis.

Horizontal bar graph to represent fruits liked by students

Vertical: Here, the bars are drawn vertically from down to top. The data categories are placed on the horizontal axis, and the numerical values are placed on the graph’s vertical axis. 

Vertical bar graph to represent student’s favorite fruit

Grouped: This graph represents related sets of data. Each set of data is graphed separately but on the same graph. The key explains which set of data is shown by the graph.

Example of Grouped Bar graph

For example, in the above graph, the blue bar represents the number of students in Class A that prefer a particular fruit, the orange bar represents the number of students in Class B, and the green bar represents the number of students in Class C that prefer a particular fruit.

How to make a Bar Graph?

Let’s try representing the given data on a graph.

School Supplies Students Use
PencilScalePenSharpenerEraser
83254

Step 1: Decide the scale and interval for your numerical values. The scale refers to the counting sequence we will place on the axis. For smaller values, we simply go with the counting sequence 1, 2, 3… but for larger values, we can also pick a counting sequence with some interval of numbers between each value. For example, 5, 10, 15… 

Step 2: Label the horizontal and vertical axes to describe the information.

Here, we are drawing a vertical bar graph, so we will place the categorical data on the x-axis and the numerical values on the y-axis.

Step 3: Draw bars corresponding to each category. For example, since there are 8 pencils, draw a rectangle over the “pencil category” with the length of the rectangle as 8 units. Similarly, draw other bars corresponding to each category with the same breadth as the first bar.

Step 4: Label the graph with a title.

How to make a bar graph

Solved Examples on Bar Graph

Example 1: Draw the horizontal bar graph for the given data set between the number of people and their preferred beverage.

Preferred Beverages
WaterTeaCoffeeOrange JuiceLemon Juice
4525302540

Solution:

Graph to represent beverage choices

Example 2: Create a bar graph for the given data set.

T-Shirt Sale During a Week
MondayTuesdayWednesdayThursdayFridaySaturdaySunday
10253040556020

Solution:

Graph to sales of a t-shirt store

Example 3: Draw a bar graph for the given data set.

Favorite Colors
ColorGirlsBoys
Red1015
Blue1211
Pink77
Green1513
Brown64

Solution:

Example of grouped bar graph

Example 4: Read the following graph and answer the questions.

Graph to represent number of students in school clubs
  1. Which is the most popular club?
  2. How many more students than the math club does the science club have?
  3. How many students are in the sports club?
  4. Find the total number of students in the clubs. 

Solution:

  1. The movie club is the most popular club.
  2. Number of students in Science Club $= 21$

Number of students in Math Club $= 15$

$21$ $–$ $15 = 6$

So, 6 more students are in the science club than in the math club.

21 students are in the sports club

Total number of students $= 15 + 21 + 16 + 25 + 23 = 100$

Practice Problems on Bar Graph

Bar Graph - Definition with Examples

Attend this quiz & Test your knowledge.

1

Use the given graph to find out the topping most liked by the students.

Bar Graph – Definition, Types, Examples, Practice Problems, Facts
20
25
5
10
CorrectIncorrect
Correct answer is: 25
The bar of sausage is the tallest bar in the given graph, which is reaching the line that says 25.
2

The given graph shows the data about the sale of the dresses over four months. One bar is missing from the graph. If 78 dresses are sold in these four months, which bar shows the number of dresses sold in July?

Bar Graph – Definition, Types, Examples, Practice Problems, Facts
aa
bb
cc
dd
CorrectIncorrect
Correct answer is: a
Total dresses $= 78$
number of dresses sold in July $= 78$ $–$ $(18 + 15 + 24) = 78$ $–$ $57 = 21$
Bar Graph – Definition, Types, Examples, Practice Problems, Facts
3

Which sport is liked by the least number of people?

Bar Graph – Definition, Types, Examples, Practice Problems, Facts
Basketball
Hockey
Badminton
Football
CorrectIncorrect
Correct answer is: Badminton
Badminton is liked by the least number of people.
4

The average marks scored by four different classes of boys and girls are shown in the given graph. What is the average score of Class C?

Bar Graph – Definition, Types, Examples, Practice Problems, Facts
70
82.5
67.5
100
CorrectIncorrect
Correct answer is: 70
Average score $= \frac{60+ 80}{2} = 70$

Frequently Asked Questions on Bar Graph

Data representation gives a clear idea of what the information means by giving it visual context through graphs. It makes the data easy to understand.

It represents the data set in a visual form, which helps to observe and analyze the data easily.

  • Line chart
  • Pie chart
  • Histogram, etc.

The title and labels give information about the number of items under certain categories which is essential for reading the graph.