How to add overlays to bar charts and column charts

Bar charts and column charts are normally limited to showing one value per category. With overlays, you can show multiple values. This is helpful to visualize different scenarios for each category, show projected versus actual values, or mark a confidence interval.

To learn how to use overlays to add confidence intervals, visit our articles 
👉 How to show confidence intervals in Datawrapper column charts
👉 How to show confidence intervals in Datawrapper bar charts

Datawrapper offers two kinds of overlay: value overlays and range overlays. Since the articles mentioned above focus on range overlays, this article will focus on explaining value overlays. 

Here's an example of a column chart with two value overlays (but you can add as many overlays as you like!): 

And here's the same data with the same overlays, but as a bar chart. Note that overlays get labeled directly in bar charts: 

How to show overlays in bar and column charts

1

Upload the data 

First, our chart needs some data. Bar and column charts normally just need two columns: One with categories, the other one with numbers. To create overlays in a bar or column chart, you'll need to upload an extra number column for each value overlay (and an extra two number columns for each range overlay). 

In our case, the data looks like this:
year same climate action more climate action less climate action
2030 +1.5°C +1.5°C +1.5°C
2040 +1.7°C +1.6°C +1.8°C
2050 +1.9°C +1.7°C +2.1°C
... ... ... ...

Upload your data in step 1: Upload data, then proceed to step 3: Visualize.

2

Prepare the column chart

Once you selected column chart or bar chart as your visualization type, continue to the Refine tab. Here you can choose which numbers you want to visualize as the actual bars or columns in your bar or column chart. Select it in the Select column dropdown:

In our case, we choose the first number column, "same climate action". Now you can customize your chart to your liking; e.g. by changing the colors, label alignment, etc. You can find more information about this in our articles Customizing your column chart and Customizing your bar chart. 


3

Add the overlay

To add a value or range overlay to your chart, scroll all the way down in the Refine tab until you see the button Add overlay. Click on it. By default, Datawrapper creates a Here you have a few options: value overlay:

Once you added an overlay, Datawrapper will give you a few options: 

  • + Add overlay lets you add another overlay. They will all appear in a list below this button. If you want to hide an overlay, click on the eye symbol. You can also delete an overlay with the click on the trash icon.  

In the settings for each overlay, ...

  • Type lets you choose which kind of overlay you want to create, a value overlay (shown in your chart as a line) or a range overlay (shown in your chart as a area between two values). 
  • Column lets you select the column that you want to add as an overlay. For our value overlays, we chose the column "more climate action" and "less climate action. 
  • Title lets you change the explanation of your overlay in your chart. By default, the column name is used – in our case, that's "less climate action". 
  • With Color, Opacity, and – in the case of range overlays – Pattern, you can change the appearance of the overlay. 
  • Label on first row shows up when you create a overlay in a bar chart. It's on by default. If you prefer to move the explanation of your overlays to the color key instead of using direct labels, simply turn it off. 

And that's it! You just created your first overlay in a bar or column chart. If you have any questions, don't hesitate to get in touch with us at support@datawrapper.de. You can also hover over the charts above and click on the "Edit this chart" button to jump right into the chart creation process.