Common Chart Design Pitfalls: Trailing Zeros

Here are several reasons why you should avoid using trailing zeros and overly precise numeric values in charts.  

1. Clutter reduction: When you include unnecessary trailing zeros or overly precise numeric values, you are adding visual clutter to your charts. This may make the chart appear more complicated than it needs to be, which can hinder the overall understanding of the information being presented. For example, displaying a bar chart with values like 5.000 or 10.00 on the labels will create more visual confusion than simply displaying 5 or 10.
2. Simplified perception: In many cases, people do not need to know the exact numeric value down to several decimal places. They only need an approximate idea of the magnitude of the value or trend. Using simplified values makes it easier for your audience to perceive and understand the data at a glance. For instance, when displaying a city’s population, using the value 1.5 million is more easily graspable than 1,493,728.
3. Focus on the key message: Overly precise numeric values can shift the focus away from the main insights and key messages you want to convey with your data visualization. Simplifying the values helps keep the audience’s attention on the primary story being told. For example, when comparing average incomes between two groups and the difference is nearly $7,500, the main takeaway is that there is a significant income gap rather than focusing on the exact dollar amount.
4. Improved comparisons: When representing data with simpler and consistent numeric values, comparisons between datasets become easier. If some values have more decimal places than others, precise comparisons can frustrate the viewer. By reducing this unnecessary detail, audiences can quickly compare data points and make sense of the relationships between them.

By simplifying your data representation, you make it easier for your audience to understand the key messages and insights, ultimately telling a more compelling data story.