When to use a Bar Chart
If you have comparative data that you would like to represent through a chart then a bar chart would be the best option. This type of chart is one of the more familiar options as it is easy to interpret. These charts are useful for displaying data that is classified into nominal or odinal categories. A good example of a bar chart can be seen below.
A bar chart uses bars to show comparisons between categories of data. These bars can be displayed horizontally or vertically. A bar graph will always have two axis. One axis will generally have numerical values, and the other will describe the types of categories being compared.
The comparison you want to make will help determine whether to display the bars vertical or horizontal. You would need to decide whether the data you are trying to represent has an intuitive direction or not.
Horizontal Bar Chart
Most bar charts are plotted vertically, meaning the taller the bar the larger the category, but the data can be plotted horizontally instead meaning the longer the bar the larger the category. This is a good way to present data with long labels that would be hard to display below a vertical bar. Also if you are trying to display a large number of data sets on the category axis, for example when you are trying to compare the amount of rainfall in a year.
Vertical Bar Chart
This is also commonly referred to as a column chart. If you was trying to compare the height of something then intuitvely you would represent this by using columns. This is generally a good chart to choose for all comparison based analysis but if you were to display a data set with negative values a column would be the best to represent this. Most people associate negative values with a downward direction, which relates back to intuitive direction, so ultimately you need to decide what you are trying to represent with your data. An example of this can be seen below.
If you want to learn how to easily make a Bar Chart with ChartBlocks then in our FAQ area we have a step by step guide of how to make charts?