Bar Graph

A bar graph is a specific way of representing data using rectangular bars where the length of each bar is proportional to the value they represent. It is a graphical representation of data using bars of different heights. In real life, bar graphs are commonly used to represent business data.

A bar graph is a graph that shows complete data with rectangular bars and the heights of bars are proportional to the values that they represent. The bars in the graph can be shown vertically or horizontally. Bar graphs are also known as bar charts and it is a pictorial representation of grouped data. It is one of the ways of data handling. Bar graph is an excellent tool to represent data that are independent of one another and that do not need to be in any specific order while being represented. The bars give a visual display for comparing quantities in different categories. The bar graphs have two lines, horizontal and vertical axis, also called the x and y-axis along with the title, labels, and scale range.

Properties of Bar Graph

Some properties that make a bar graph unique and different from other types of graphs are given below:

• All rectangular bars should have equal width and should have equal space between them.
• The rectangular bars can be drawn horizontally or vertically.
• The height of the rectangular bar is equivalent to the data they represent.
• The rectangular bars must be on a common base.

Uses of Bar Graph

A bar graph is mostly used in mathematics and statistics. Some of the uses of the bar graph are as follows:

• The comparisons between different variables are easy and convenient.
• It is the easiest diagram to prepare and does not require too much effort.
• It is the most widely used method of data representation. Therefore, it is used by various industries.
• It is used to compare data sets. Data sets are independent of one another.
• It helps in studying patterns over long periods of time.

Bar Graphs are mainly classified into two types:

• Vertical Bar Graph
• Horizontal Bar Graph

The bars in bar graphs can be plotted horizontally or vertically, but the most commonly used bar graph is the vertical bar graph. Apart from the vertical and horizontal bar graphs, there are two more types of bar graphs, which are given below:

• Grouped Bar Graph
• Stacked Bar Graph

Let us understand all the types of bar graphs in detail.

Vertical Bar Graphs

When the given data is represented vertically in a graph or chart with the help of rectangular bars that show the measure of data, such graphs are known as vertical bar graphs. The rectangular bars are vertically drawn on the x-axis, and the y-axis shows the value of the height of the rectangular bars which represents the quantity of the variables written on the x-axis.

Horizontal Bar Graphs

When the given data is represented horizontally by using rectangular bars that show the measure of data, such graphs are known as horizontal bar graphs. In this type, the variables or the categories of the data have to be written and then the rectangular bars are horizontally drawn on the y-axis and the x-axis shows the length of the bars equal to the values of different variables present in the data.

Stacked Bar Graph

The stacked bar graph is also referred to as the composite bar graph. It divides the whole bar into different parts. In this, each part of a bar is represented using different colors to easily identify the different categories. It requires specific labeling to indicate the different parts of the bar. Thus, in a stacked bar graph every rectangular bar represents the whole, and each segment in the rectangular bar shows the different parts of the whole. It can be shown vertically or horizontally.

Grouped Bar Graph

The grouped bar graph is also referred the clustered bar graph. It is used to show the discrete value for two or more categorical data. In this, rectangular bars are grouped by position for levels of one categorical variable, with the same colors showing the secondary category level within each group. It can be shown both vertically and horizontally.

Observe the figure given below which shows different types of bar graphs.

Let us understand how to draw a bar graph with help of an example. Liza went to the market for buying different types of fruits in different quantities of each- 5 apples, 3 mangoes, 2 watermelons, 3 strawberries, 6 oranges. She wants to display the data by making a bar graph so that she can visually understand which type of fruits she buys the most.

Let us use the following steps to make a bar graph of the most bought fruit.

• Step 1: Take a graph paper and give the title of the bar graph like "Most Bought Fruit".
• Step 2: Draw the horizontal axis (x-axis) and vertical axis (y-axis) on a plane.
• Step 3: Now label the horizontal axis as "Types of Fruits" which is an independent category and the vertical axis as "Number of Fruits" which is a dependent category.
• Step 4: Label the fruits' names such as apples, mangoes, watermelon, strawberries, oranges and give an equal gap or leave equal space between each fruit on the horizontal axis.
• Step 5: Give the scale of the graph which shows the way in which numbers are used in the data. It is a system of marks at fixed intervals which helps in measuring objects. For example, the scale of a graph can be written as 1 unit = 1 fruit.
• Step 6: Now start making rectangular bars with equal gaps for each fruit and give height to their respective numbers.
• Step 7: The bar graph is ready, observe the height of rectangular bars of each fruit and find out the most bought fruit.

While drawing a bar graph it is very important to mention four things - labels on axes, title, scale, and name of the axes.

From the above graph, we can easily say that orange is the most bought fruit that Liza buys.

Bar Graph vs Histogram

The basic difference between histograms and bar graphs is that the bars in a bar graph are not adjacent to each other whereas, in histograms, the bars are adjacent. A bar graph is the graphical representation of precise data using rectangular bars with equal gaps between them whereas a histogram is the graphical representation of data that is represented by rectangular bars with no gaps between the bars.
Histograms are used to represent distributions of variables and plot quantitative data such as data of the population changes every year, marks obtained, monthly salary whereas bar graphs are used to compare various variables and are used to plot categorical data such as data of types of animals, types of colors, types of movies, etc.

Tips on Bar Graphs:

Given below are some important tips related to bar graphs.

• There must be equal spacing between the bars.
• First, understand the data presented on the x-axis and y-axis and the relation between the two in terms of the length of the bars.
• If the frequency of data is very large, then bar graphs are always advisable since pictographs become time-consuming and very difficult to make.

☛ Related Articles

• Data Handling
• Line Graphs
• Stem and Leaf Plot
• Pie Charts

What is a Bar Graph in Math?

A bar graph is a way of representing data using rectangular bars where the length of each bar is proportional to the value that it represents. It is a graphical representation of data using bars of different heights.

What is the Difference Between a Bar Graph and a Histogram?

The difference between histograms and bar graphs is that the bars in a bar graph are not adjacent to each other. On the other hand, in a histogram two consecutive bars are adjacent. In a bar graph, there must be equal spacing between the two consecutive bars whereas in a histogram, the bars should be attached to each other and the X-axis should show only continuous data only in terms of numbers.

What are the Uses of Bar Graph?

Bar Graph is used in mathematics, accounting, economics, and statistics. A bar graph makes comparisons between different variables easily and conveniently and helps in analyzing patterns over long periods of time.

What are the Similarities Between Bar Graphs and Histograms?

The similarities between bar graphs and histograms are that they both have an x-axis and y-axis. They use vertical or horizontal rectangular bars to display data. The height of the bars is according to the relative frequency of the numbers of data given in the element.

What are the Types of Bar Graph?

There are four types of bar graphs: vertical bar graph, horizontal bar graph, stacked bar graph, and grouped bar graph.

• Vertical Bar Graph: It represents the grouped data vertically.
• Horizontal Bar Graph: It represents the grouped data horizontally.
• Stacked Bar Graph: Each bar in the graph is a whole, and the segments or breaks in the bar are the different parts of that whole.
• Grouped Bar Graph: It allows to compare categories with the same level and use the same colors to compare the groups within them.

What is the Difference Between Bar Graph and Pie Chart?

The bar chart shows discrete data while comparing one data point with another, whereas the pie chart is the type of graph in which a circle is divided into parts and each part is a fraction of the whole.

What is the Difference Between Bar Graph and Line Graph?

A line graph is a graph that is used to show information when a series of data is connected by a line whereas a bar graph is a particular way of representing data using rectangular bars where the height of each bar is proportional to the value it shows in data. Bar graphs display the relationships between the data quickly, whereas, line graphs plot too many lines over the graph and sometimes make it confusing to read.

What is Stacked Bar Graph?

A stacked bar graph uses rectangular bars to display comparisons between categories of data and it has the ability to break the bar and compare the parts of a whole. Each rectangular bar in the graph represents a whole, while the segments in the bar represent different parts of that whole.

What are the Properties of a Bar Graph?

The properties of a bar graph are as follows:

• All bars must be of equal width.
• The bars can be drawn horizontally as well as vertically as per the requirement.
• The height of the bar is proportional to the data they represent.
• All bars must share a common base.

What is the Disadvantage of Bar Graph?

The disadvantage of a bar graph is that it often requires additional explanation and fails to expose key assumptions, causes, impacts, and patterns. Also, it can be easily manipulated by misleading information.

How are Bar Graphs Used in Real Life?

In business, people use bar graphs to present information, such as sales information, to customers as well as to employees. People also use bar graphs for personal reasons, such as keeping track of finances, etc.

What are the Parts of a Bar Graph?

The different parts of a bar graph area as follows:

• Horizontal axis
• Vertical axis
• Title of the bar graph - which explains what the graph is all about.
• Title of the Horizontal axis - shows the data represented on it.
• Title of the Vertical axis - shows the data represented on it.
• The categories on the specific axis - show what each bar stands for.
• The scale of the bar graph - shows the way in which numbers are used in the data. It is a system of marks at fixed intervals which helps in measuring objects. For example, the scale of a graph is written as 1 unit = 10 children.

What is the Title of the Bar Graph?

The title of the bar graph shows what the graph is about. It represents the information which we ultimately conclude from the given graph. For example, the favorite color of students, car prices, or cakes sold in a week.