Column chart
Description
In a column chart, each category is represented by a vertical rectangle, with the height of the rectangle being proportional to the values being plotted. It’s a vertical version of the bar chart, also sometimes called a vertical bar chart.
When to use
The column chart is widely used to show comparison among categories and sometimes to visualize time-based data. It’s effective for showing the difference between values.
Dos and donts
Always start at a zero baseline.
Use consistent colours throughout the chart, using accent colours to highlight meaningful data points.
Choose either axis label or data label.
Use horizontal labels to improve readability.
Space between bars should be roughly half of the bar width.
Tools available
MS Office Power BI Illustrator R D3.js Python
Bar chart
Description
A bar chart is a chart in which each category is represented by a horizontal rectangle, with the length of the rectangle proportional to the values being plotted. The horizontal axis shows data value, and the vertical axis displays the categories being compared. It’s a horizontal version of the column chart.
When to use
The bar chart is widely used to show comparison among categories and sometimes to visualize time-based data. It’s effective for showing the difference between values. It’s an alternative to the column chart when the category name is long.
Dos and donts
Always start at a zero baseline.
Use consistent colours throughout the chart, using accent colours to highlight meaningful data points.
Choose either axis label or data label.
Sort the data in descending order before charting for non-ordinal data.
Space between bars should be roughly half of the bar width.
Avoid using bar charts if most of the values are negative. It is better to use column charts unless the labels do not fit underneath the bars.
Tools available
MS Office Power BI Illustrator R D3.js Python
Grouped column chart
Description
Grouped column charts are a type of colour-coded column chart used to represent and compare different categories of two or more groups.
When to use
It’s used when two or more categories are grouped and arranged side-by-side, the grouped vertical bars make it easy to interpret the differences inside a group, and even between the same category across groups.
Dos and donts
Always start at a zero baseline.
Order of the elements in a legend should be in the same sequence as the bars for easy reference.
Don’t plot more than 3 groups.
Leave enough space between two groups of bar charts in order to easily differentiate between the groups.
Tools available
MS Office Power BI Illustrator R D3.js Python
Grouped bar chart
Description
Grouped bar charts are a type of colour-coded bar chart that is used to represent and compare different categories of two or more groups.
When to use
Grouped bar charts are used when two or more categories are grouped and arranged side-by-side. The grouped bars make it easy to interpret the differences inside a group, and even between the same category across groups. It’s an alternative to grouped column charts when the category names are long.
Dos and donts
Always start at a zero baseline.
Order of the elements in a legend should be in the same sequence as the bars for easy reference.
Don’t plot more than 3 groups.
Leave enough space between two groups of bar charts in order to easily differentiate between the groups.
Tools available
MS Office Power BI Illustrator R D3.js Python
Stacked column chart
Description
The stacked column chart stacks vertical bars that represent different groups on top of each other. The height of the stacked bar shows the combined value of the groups. They show the cumulative values of a data item and compare parts to the whole.
When to use
It’s particularly useful when comparing relative and absolute changes over time. However, stacked column charts are not suited to datasets where some groups have negative values. In such cases, grouped column charts are preferable.
Dos and donts
Always start at a zero baseline.
Elements in the legend should be in the same sequence as the bars.
Don’t stack too many groups at once (five or fewer is ideal).
Use horizontal labels to improve readability.
Space between bars should be roughly half of the bar width.
Tools available
MS Office Power BI Illustrator R D3.js Python
Stacked bar chart
Description
Stacked bar charts stack horizontal bars that represent different groups one after another. The length of the stacked bar shows the combined value of the groups. They show the cumulative values of data items and compare parts to the whole.
When to use
Stacked bar charts are used to show how a larger group is divided into smaller subgroups and what the relationship of each part has on the total amount. It’s particularly useful when comparing relative and absolute differences across categories. It’s a better option when the category names are long and do not fit underneath of vertical stacked bar chart (stacked column chart).
Dos and donts
Always start at a zero baseline.
Elements in the legend should be in the same sequence as the bars.
Don’t stack too many groups at once (five or fewer is ideal).
The data should be sorted by total value in descending order when using a stacked bar chart for categorical variables (non-ordinal variables).
Space between bars should be roughly half of the bar width.