Introduction to treemaps

A treemap is a data visualization technique that displays hierarchical data in a nested, rectangular form. It is particularly useful for representing hierarchical structures and illustrating the proportion of each branch in relation to the whole. The primary goal of a treemap is to provide a visual representation of the hierarchical structure and to convey the relative sizes of the different elements within that structure.

Compared to other proportional chart types, such as pie charts, treemaps work well for richer datasets with more data points. They provide a clear and concise way to communicate complex hierarchical relationships and enable users to quickly grasp the overall structure and distribution of data.

Flourish treemaps

With Flourish, you can create an interactive and engaging treemap for free by simply uploading a spreadsheet. You can decide how many levels of hierarchy to show at once, customize the color palette and fonts of your visualization, as well as add a filter based on a column in your data.

The individual areas of a treemap are fully zoomable, revealing more detail. Popups help you highlight key information in your visualisation - and with Flourish, you have full control over when to show popups.

Additionally, you can choose between different treemap layout styles and size the shapes either by numerical values in your data or simply by the count of entries in each group.

Types of hierarchy charts

Besides a treemap, Flourish offers multiple other options of visualizing your hierarchial data.

Data structure for a treemap

To build a treemap, your data should be in a long format, meaning each row represents a single data point and each column represents a variable. The first column(s) A-C should contain the information to nest your data by. They should be followed by a numerical column D to size the rectangles by.

Read our help doc to learn more.






Income classification




Upper middle income

East Asia & Pacific


United States

High income

North America



High income

Europe & Central Asia



Lower middle income

Sub-Saharan Africa


Country population and income classification


Here are some resources to help you get started with treemaps:

Hierarchy – an overview
How to size by multiple values
How to add prefixes and suffixes to values
Introducing Flourish treemap visualizations

Make a treemap now

Explore and explain your data with stunning visualizations and stories. Publish, present or download. No need to code or install software.