How to create a choropleth map
A choropleth map is a map in which areas (like states or countries) are filled with colors according to your data. Let's assume you want to map unemployment rates in the U.S. A choropleth map is perfect for that. The darker the color, the higher the unemployment rate:
This tutorial walks you through the steps to prepare and import data for a choropleth map in Datawrapper. We have a separate tutorial on how to create a symbol map.
Choose a map
To create a map, go to app.datawrapper.de/create/map and select Choropleth map.
The first question that Datawrapper will ask you after you've decided on a choropleth map, is: "What type of map do you want to create?"
Even if you know that you want a U.S. map, you can still decide between different levels, e.g. states, counties, district courts, or congressional districts – and sometimes even different years.
We know that we want to make a US county map, so we'll search for "USA", click on USA » counties (2018) and then click Proceed.
Prepare the data
Before we can visualize the unemployment rates, we need to bring them in the right format. Datawrapper will need a table with at least two columns:
- The key of each region you want to fill with a color. Most often, that's the name, like county names. But for some regions, we have specific IDs, e.g. the FIPS-Code for counties in the US (which we'll use).
- The value for each region. The values can be percentages (43.4%), full numbers (38430), or categories (yes/no/maybe). Our table will have the column "Unemployment Rate" with numerical values.
Here is our table (data is from the US Bureau of Labour Statistics, August 2017). As you can see, we have a third column, "County". In fact, we can have as many columns as we like, as long as one of them has a map key and one of them has some kind of value. Extra information like the name of the county can be useful for tooltips, so we want to keep them in our table.
| Barbour County
Import the data
Once you prepared the data, let's add it to your map! You'll find all the options to do so in the Upload tab in step 2: Add your data:
Here are all the ways to import your table:
- Write your values directly into the Datawrapper table. This takes a long time, so this works best for maps with only a few regions.
- Upload a CSV or Excel file. To do so, click on Upload file.
- Copy & paste your data into the text field in the Upload tab, e.g. from Excel or Google Sheets. This is the most convenient option for lots of our users.
- Link an external dataset. That's the best option if your data keeps updating (e.g. election results during election night), and you want your embedded map to always show the latest numbers. Learn more in our article "How to create a live-updating choropleth map".
- Import a Google Spreadsheet. That's a good option if you or a coworker is changing the data by hand a lot and you want to make sure that your map shows the latest numbers when visualizing it. Learn more in our article "How to connect your choropleth map to Google Sheets".
You can also fill the table with random data if you just want to try out our tool.
Match & check the data
Some of your regions might have a different key in your data than in our map – e.g. "Czechia" instead of "Czech Republic". Datawapper will highlight the regions it couldn't match in your data set, and let you correct them.
Simply click on a highlighted cell to choose any of the yet-unmatched regions. You can also delete rows – or edit the text and numbers in cells by double-clicking on it:
You can also go to the Check tab to see all unmatched regions in an overview.
👉 Each map will have specific keys, and we recommend checking which ones are accepted at the beginning of your data preparation process. You'll find the accepted keys in the Match tab. There, you can also download a CSV with all possible keys for the map.
If you successfully imported and matched the data, click on Proceed to go to step 3: Visualize. Here you can tweak the colors, title, map key, zoom buttons etc. We will cover this part in the next tutorial: Customizing your choropleth map.