A Bar Graph (also called a Bar Chart) is a visual way to show data using rectangular bars. Each bar represents a group or category, and the length or height of the bar shows the value or amount. This makes it easier to understand and compare information quickly. Bar graphs are commonly used in Data Interpretation and are an important part of many competitive exams.

There are six main types of bar graphs, and they are grouped based on how they look and how much information they show for each category. Some bar graphs show just one value for each group, while others show two or more values side by side.

What are Bar Graphs?

A Bar Graph is a type of graphical representation used to show and compare information clearly using rectangular bars. It is based on numbers and data and is often used in maths and statistics to make information easier to understand. A bar graph uses two lines, called axes – the x-axis (horizontal) and the y-axis (vertical).

One axis shows the categories or items we are comparing (like months, fruits, or people), while the other axis shows the numbers or values related to those categories. Each category is represented by a bar, and the height or length of the bar shows how big or small the value is. The bigger the value, the taller or longer the bar will be.

Bar graphs help us quickly see differences or trends in data and are often used in schools, businesses, and exams for data interpretation and comparison.

Learn about Simple Bar Graph here.

Bar graphs are majorly used to compare various observations based on a certain parameter(s). Based on the structure of the bars and the number of parameters, the bar graph is classified into the following six types.

• Horizontal bar graph
• Vertical bar graph
• Double bar graph (Grouped bar graph)
• Multiple bar graph (Grouped bar graph)
• Stacked bar graph
• Bar line graph

Let us now discuss these in detail.

Horizontal Bar Graph

When the Y-axis represents the observation to be compared, and the x-axis represents the magnitude of the observations, then the bars run horizontally along the x-axis up to the point of value proportional to the observation. Such a bar graph is known as a horizontal bar graph.

Example- In the horizontal bar graph given below the percentage of four students is shown.

Vertical Bar Graph

Vertical bar graphs are just the opposite of horizontal bar graphs. Vertical bar graphs are preferred more than horizontal bar graphs.

Here, the x-axis represents the observation/category which is usually a fixed variable. The y-axis represents the numerical values that the observation carries. The bars start from the x-axis and run vertically along the y-axis up to the point of value proportional to that particular observation.

Example- if we take the same example as above, the vertical bar graph will look something like the following:

Also know about Bar Line Graph here.

Grouped Bar Graph 

Both the above types discussed until now were simple bar graphs that were plotted on the basis of only one parameter. In the above two examples, the student is the observation that is being compared, while the percentage is the parameter that is the basis of comparison.

A grouped bar graph gives you the advantage to compare various observations on the basis of more than one parameter. Based on the number of parameters used, grouped bar graphs can be further classified into two types.

• Double bar graph
• Multiple bar graph

Double Bar Graph

In a double bar graph, as the name suggests, you can make a comparison among various observations or categories using two parameters. However, those two parameters should be measured in similar quantities, which means that they should be of the same unit.

In a double bar graph, two bars are drawn for each observation. You must plot the two bars with two different and contrasting colors to emphasize the difference. You must also mention on the graph what each color represents.

Example- the following double bar graph shows the sales percentage and profit percentage of five stores

Multiple Bar Graph

Again, as the name suggests, in a multiple bar graph, you can make a comparison among various observations on the basis of multiple parameters. You can include as many parameters as you wish, however, each parameter should have the same unit of measurement.

In a multiple bar graph, there are as many bars for each observation as there are parameters. For instance, if the marks of six students are being compared in four subjects, then for each student there will be four bars drawn.

Example- The following multiple bar graph shows the marks in 4 subjects of six students.

Learn about Multiple Bar Diagram

Stacked Bar Graph

A stacked bar graph also represents various parameters in a single graph. The difference is that in a stacked bar graph all the parameters are represented in a single bar. So you can say that there are segments of a total in a single bar.

A stacked bar graph has the ability to convey a lot of information all together in a compact and precise format. However, stacked bar graphs are rarely used because they can be confusing at times while representing too much information.

Example- The following stacked bar graph shows the number of red candies, blue candies, green candies, and yellow candies sold by four teams in a fete.

Bar Line Graph

A bar line graph is a combination of a bar graph and a line graph. It is a type of grouped bar graph. In this type of bar graph also you can compare observations on the basis of more than one parameter. The difference is that you can take the parameters of different units in this type.

For example, in this case, if you want to compare the students on the basis of their marks in one subject and their total percentage, you can do so. For this, you have to draw two y-axes. One y-axis will represent one parameter and the other will represent the second parameter. The bars will be plotted according to one y-axis and the line will be plotted according to the other y-axis.

Example- the following bar line graph shows the percentage and marks in Science of 4 students of a class.

How to Draw a Bar Graph

Step 1: Choose the Data Categories
Start by deciding what you want to show in your graph. These could be product names, months, survey answers, or any group you want to compare.

Step 2: Label the Axes
Draw two lines that cross each other — one across (x-axis) and one going up (y-axis). Write the names of the categories on the x-axis and use the y-axis for numbers or values.

Step 3: Decide the Scale
Pick a number scale for the y-axis. The numbers should be spaced out well and match the highest value in your data. Make sure the scale is easy to read.

Step 4: Draw the Bars
Above each category name on the x-axis, draw a bar that reaches up to the matching value on the y-axis. All bars should have equal width and be neatly drawn.

Step 5: Add Colours or Patterns
Use different colours or patterns for each bar. This helps tell them apart quickly. Choose colours that are clear and easy to see.

Step 6: Label Everything
Write labels on or near each bar if needed. Also, make sure the graph has a title, and both the x-axis and y-axis are clearly labelled.

Step 7: Add a Legend (if needed)
If you used colours or patterns to show different groups, include a small box (legend) that explains what each colour or pattern means.

Step 8: Check and Improve
Take a final look at your bar graph. Make sure it’s clear, correct, and easy to read. Fix anything that looks confusing or messy.

Properties of Bar Graph

The following are the major properties of a bar graph:

Vertical or Horizontal Bars: A bar graph may contain vertical or horizontal bars. In the case of a vertical bar graph, the bars are vertically plotted on the y-axis, whereas in a horizontal bar graph, the bars are horizontally plotted along the x-axis.

Bar Height or Length: Each bar's height or length denotes a certain value or amount related to the respective category or variable being depicted. The height or length of the bar corresponds with the extent of the data it depicts.

Equal Width: In a bar chart, the width of the bars is often constant. It provides the visual comparison of the lengths of bars to accurately show differences between the values of data.

Categorical Data: Bar charts are especially used to represent categorical data, in which each bar is a different category or variable. The categories are commonly shown along the x-axis (for vertical charts) or the y-axis (for horizontal charts).

Spaces Between Bars: There is typically a narrow space between the adjacent bars of a bar graph. This space serves to visually separate individual bars and avoid them running into each other as a line.

Axes Labels and Scales: Bar graphs have labels on the categories for the x-axis (or y-axis for horizontal bar graphs) and numbers labels on the y-axis (or x-axis for horizontal bar graphs). The axes scales serve as a reference point to interpret the values being represented by the bar lengths or heights.

Colour or Patterns: Various colours or patterns are usually employed in bar graphs in order to distinguish between bars from various categories or variables. This improves the visual discrimination and facilitates easier recognition and comparison of the data.

Title and Captions: A bar graph will often contain a title that indicates the aim or topic of the graph. Legends or captions may also be employed to relate extra information about the data presented.

Applications of Bar Graphs

Bar graphs have numerous uses in various areas because of their ease and ability to depict categorical data. Some of the frequent uses of bar graphs are as follows:

Data Comparison: Bar graphs are extensively used to compare data from different categories or variables. They enable simple comparison of values visually, making it easy to detect patterns, trends, and data set differences. Bar graphs are popularly employed in market research, sales analysis, and performance assessment.

Survey Results: Bar graphs are ideal for displaying survey results or opinion polls. A bar represents a response option or category, and the height or length of the bar indicates the frequency or percentage of people selecting that option. Bar graphs enable easy interpretation and comparison of the distribution of responses.

Population Statistics: Bar graphs are generally used to present population statistics, including demographic information, age distribution, or educational levels. Each bar will indicate a single category, e.g., age groups or education levels, so the distribution of the population can be shown visually.

Financial Analysis: Bar charts are useful in financial analysis to present monetary data, like revenue, costs, or profit between various time intervals or company divisions. They show clearly the financial performance, and therefore trends are easily determined and decisions are well-informed.

Inventory Management: Bar graphs are applicable in inventory management to monitor and compare different products or inventory items. Every bar shows a product or item, and the height of the bar reflects its quantity or stock level. Bar graphs assist in determining low or high stock levels and controlling inventory.

Academic Performance: Bar graphs can be used to show academic performance information, e.g., grades or test scores of pupils. This can easily compare performance between subjects or pupils and help in the determination of areas for improvement or areas of strength.

Sports Statistics: Bar graphs are applied in sports statistics to depict statistics like goals scored, assists, or the performance of a player. Every bar is intended to represent a player or team, and the size of the bar corresponds to the respective statistic, allowing for comparisons and analysis.

Features of a Bar Graph

1.Bar Height Shows Value:
The taller or longer the bar, the larger the value it represents.

2.Bar Width is Fixed:
The width of each bar stays the same. It doesn’t change with the value—only the height or length does.

3.Width Can Depend on Space:
The width of bars can be chosen based on how many bars need to fit in the graph so that everything looks neat and organized.

4.Equal Gaps Between Bars:
All bars are evenly spaced, so the graph is easy to read and compare.

5.Bars Can Go Up or Sideways:
Bars can be drawn vertically (up and down) or horizontally (side to side). Most bar graphs use vertical bars.

6.Axes of the Bar Graph:

The y-axis (side) shows the values (like amounts or numbers).

The x-axis (bottom) shows the types or categories of data.

Advantages of Bar Graphs

1. Easy to Make and Understand

Bar graphs are simple to draw on paper or using software. You just need data to compare, and you can choose the right type:

Vertical bars for fewer items

Horizontal bars for many items

Stacked bars to show parts of a whole

Grouped bars to compare across time

Labeling the x-axis and y-axis is also straightforward.

2. Used in Many Fields

Bar graphs are used everywhere—from businesses to science:

In healthcare, to track how diseases spread

In business, to look at sales and finances

Even in personal life, to keep track of spending

3. Helps Compare Data Easily

Bar graphs help you see differences between data quickly. For example, you can use a stacked bar graph to compare online and offline sales each month. This helps businesses know which area needs more focus.

4. Summarizes Large Data Clearly

If you have a lot of information, a bar graph can show it clearly in one picture. For instance, a company might track delivery times during busy and quiet seasons using a grouped bar graph.

5. Shows Trends and Patterns

Bar graphs make it easy to spot patterns over time. Unlike a table full of numbers, a bar graph lets anyone see trends like rising sales or falling profits just by looking at the bars.

Disadvantages of Bar Graphs

1. May Need Extra Explanation

Bar graphs are great for showing basic data, but for more complicated topics, they might not be enough. You often need extra explanation or examples to fully understand what the graph is showing.

2. Can Be Misleading

Because bar graphs are easy to change, they can sometimes be used to mislead people. For example, changing the scale on the axes can make small differences look big or vice versa. This is especially a problem on social media or in advertisements.

3. Don’t Show Relationships Between Tasks

Bar graphs can show how long tasks take, but they can’t show how tasks are connected. This makes them less helpful for managing complex projects where knowing how things depend on each other is important.

4. Can’t Track Progress Well

A bar graph can show planned work but not how much has been done. It doesn’t show delays or changes, which makes it hard to use in fast-moving or flexible projects.

Difference between Bar Graph and Histogram

We hope that you understood the different types of bar graphs, the difference between them, and how to draw them through this article. If you have any other doubts or suggestions for us then you can contact us on the details given at the end of this page. If you wish to access more such learning material then you can download the Testbook App. With Testbook you can prepare for any government exam from the comfort of your house. On our app, you can get video tutorials, live interactive classes, mock tests, and other such perks. So hurry up and download the app from the play store NOW!