Why our column and bar charts start at zero (or below)

This article explains why you can't set the minimum range of your column and bar charts to something greater than zero. At the bottom of the article, you can find alternatives to a truncated y-axis that still let you show your data well.

Why our column and bar charts start at zero 

Truncated y-axes in column charts and bar charts are considered deceptive and misleading. And there's research backing that up. Have a look at these two column charts: How much do you think is the orange bar is bigger than the blue bar? 

That's the question that Pandey, Nov, Rall, Bertini, and Satterthwaite asked their participants about a very similar chart in a study from 2015 that they wrote up in the paper "How Deceptive are Deceptive Visualizations?" They found a significant distortion: "participants who saw the deceptive visualization perceived the underlying message in its exaggerated form". Starting a column chart at something greater than zero and similar deceptive techniques "do lead to major misinterpretation from the reader’s side and that the effects are also rather large."

We have a responsibility towards your readers – we don't want them to be misled. That's why Datawrapper doesn't allow you to begin your y-axis at something greater than zero.  

Alternatives to a truncated y-axis in column/bar charts

But there's a reason why you would want to truncate your y-axis in the first place: Often, the differences between your bars or columns are barely visible if you start the axis at zero. Here are alternatives you can consider:

Use a dot plot

Readers don't expect dot plots (or, for two values, range plots) to start at zero because there's no filled bar or column that would indicate that. So you can set a custom range in our dot/range plots that start at a number greater than zero. Learn how to create a Datawrapper dot plot here.

Use a line chart

If your columns or bars have an inherent order (e.g. years or months), you can show them as a line chart. Like dot plots, line charts can but don't need to start at zero (you can read arguments for that in this Quartz piece). Learn how to create a Datawrapper line chart here.

Show the differences between the bars/columns

If you want or need to use a column or bar chart, you can change the underlying values to make it work anyway. For example, you can calculate the differences between the bars/columns. Note that this only works if your columns can be ordered, e.g. by years or months.