Horizontal Bar Graph

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

1. Drawing the vertical x-axis and the horizontal y-axis
2. The category for comparison is placed on the y-axis, and the measure of the subject is on the x-axis
3. Plotting the vertical X-axis and then the horizontal Y-axis up to the length that is proportional to the value
4. Selecting different colors for each category
5. 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.

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
Train	11	33	66	44	6
Walking	30	23	11	9	25