A horizontal bar graph, also known as a horizontal bar chart, is similar to a regular bar graph with the difference that the data are represented horizontally. Mathematically, the x and the y-axis of a horizontal bar graph are switched compared to the vertical bar graph.

Similar to conventional bar graphs, here, the length or height of each bar is proportional to the values they represent. The x-axis represents the values corresponding to each data category, while the y-axis shows the different categories of data.

Scale

The scale of a bar shows the relation between the unit lengths of the bar and the data provided in the graph. It refers to numbers that indicate certain intervals on a graph.

For example, a graph where 1 unit = 10 students, 2 units = 20 students, and so on.

Steps

Drawing the vertical x-axis and the horizontal y-axis

The category for comparison is placed on the y-axis, and the measure of the subject is on the x-axis

Plotting the vertical X-axis and then the horizontal Y-axis up to the length that is proportional to the value

Selecting different colors for each category

Adding the labels and title of the graph

Solved Example

Here is a horizontal bar graph showing the survey result representing the mode of transport availed by 100 students in a class.

Modes of Transport

Number of Students

Bus

26

Car

41

Train

14

Bike

7

Walking

12

Types

Horizontal bar graphs can be of 3 types:

Simple Horizontal Bar Graphs

Here, the categories are compared based on a single parameter. The graph plotted above is an example of a simple horizontal bar graph. Let us plot a simple horizontal bar graph with the data collected from 100 students in a class:

Sports Preferred

Number of Students

Football

26

Baseball

41

Swimming

14

Basketball

7

Athletics

12

Double Horizontal Bar Graphs

In this type of graph, we can compare different categories based on two parameters. For example, it can compare the modes of transport preferred by 100 students of grade 4 to grade 8.

Number of Students

Modes of Transport

Grade 4

Grade 5

Grade 6

Grade 7

Grade 8

Bus

15

29

10

19

47

Car

44

15

13

28

16

Multiple Horizontal Bar Graphs

As the name suggests, here we can compare categories based on more than 2 parameters. For example, it can compare the modes of transport preferred by 100 students of grade 4 to grade 8.