Stacked Graph

Area graph, Stacked bar graph, Stacked column graph

This type of visualisation depicts items stacked one on top (column) of the other or side-by-side (bar), differentiated by coloured bars or strips. A stacked graph is useful for looking at changes in, for example, expenditures added up over time, across several products or services. The graph integrates different data sets to create a richer picture of (the sum of) changes.

Items are "stacked" in this type of graph allowing the user to add up the underlying data points. Stacked graphs should be used when the sum of the values is as important as the individual items. Stacked graphs are commonly used on bars, to show multiple values for individual categories, or lines, to show multiple values over time. Thus, stacked graphs must always work with positive values.

Stacked bar graphs are often used in evaluation to show the full scale of survey responses, from Strongly Disagree to Strongly Agree, for each survey question. There are two options with the stacked graph – one that shows individual elements (raw data) and one that shows results as a percentage. For the latter, the stacked values should add to 100%.

Stacked line graphs often show how quantities have changed over time, such as school racial composition, where each racial category would correspond to a strip in the graph.

While stacked graphs are helpful for conveying multiple levels of meaning simultaneously, they also have some drawbacks. Though it is fairly easy to interpret the values for the first bar or first strip in the graph, it can be difficult to judge the exact widths of any subsequent strips, or to compare the widths of two strips. If accuracy or comparisons are of primary importance, a line graph might be the better option.


Stacked bar chart teaching example

Stacked Bar Chart Teaching Example, David Shellard & Mark Vogelgesang

Source: David Shellard & Mark Vogelgesang

2D stacked column chart​

Made in Microsoft Excel


Advice for CHOOSING this option

Stacked graphs display cumulative values. Thus, consider whether it makes sense to add up your values; for example, it is again better to use a line graph rather than adding the price of one company to the price of another, or adding the prices of products over time. 

Advice for USING this option

Because stacked graphs can be hard to interpret, it may be best to use them in analysis and first decide whether the graph will be meaningful during reporting. It can be most meaningful if there is an obvious pattern in the graph or if the stacked bars are ordered from greatest to least according to one of the quantities in the stack. Consider whether a stacked bar or column is appropriate; in cultures where people read from left to right, a stacked bar chart (rather than a stacked column) may be more easily interpretable. There is no right answer, try both to see which one works best for your data.

As for whether to show percentages or raw data, that is also a decision to make based on the data and desired message. A good test is whether your data points are part of a whole (thus you would choose percentage) or comparison points that wouldn’t naturally be summed as a percentage (e.g., total widgets produced by shift).



Many Eyes Stack Graph ToolThis tool from Many Eyes allows the user to input data of their choice and then create a stack graph using two different options.

Other ways to visualise changes over time

Line Graph
Displaying information as a series of data points connected by straight line segments, on two axes.

Comparing change between two points in time with a line.

Split Axis Bar graph
Regraphing comparison between two points in time by simply graphing the change that has occurred in that time frame.


IBM, Many Eyes: Stack Graph, Stack Graph Guide. Retrieved From

Stacked area chart vs. line chart – the Great Debate by Andy Kriebel

Jon Peltier discusses alternatives to a stacked bar chart

Quantitative Displays for Combining Time-Series and Part-to-Whole Relationships by Stephen Few

Updated: 1st October 2014 - 9:35am
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A special thanks to this page's contributors
Banana hill.
United States of America.
Research Assistant, RMIT University.


Anonymous's picture

We are a homeschool organization.  We are trying to build a chart that can add up each lesson by how far each student is alone in each one of their text books by taking an average of how far along are in each subject/text book based on the total of pages for each book, that an average of each book to the total completion for the semester.   Can you do this for us, and how much will you charge?   I can create how I want it to look on a PPT slide and send to you. 

Alice Macfarlan's picture
Alice Macfarlan

Hi Edward,

Thanks for your comment. Unfortunately we don't offer such a service through BetterEvaluation, however you might find Stephanie Evergreen's (one of this page's author's) site more useful -



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