Designing Charts: Setting Aspect Ratio and Chart Types

The aspect ratio plays a significant role in how easy it is to understand and interpret the information in a chart. The aspect ratio is the ratio of the width to the height (width:height) of the chart. The aspect ratio is important because different aspect ratios will make changes in the data appear visually larger or smaller. 

By following some simple rules of thumb and recognizing the most effective aspect ratios for different charts, you can create visually appealing visualizations that are easy to comprehend and avoid misrepresenting your data.

  • Bar charts: Try to maintain a 16:9 or 4:3 aspect ratio for bar charts. Using these ratios, horizontal bar charts can represent categories effectively and give each category sufficient space for labels. For example, when visualizing the top-selling products in a store, a horizontal bar chart with a 16:9 aspect ratio would present the names of the products without overlapping or compromising readability. 
  • Line and area charts: The ideal aspect ratio may vary depending on the data being presented for line and area charts. A 16:9 ratio is generally suitable, as it allows for a comprehensive view of the data over time or other continuous variables. For example, displaying a company’s revenue over several years with a 16:9 aspect ratio will let viewers easily observe trends and patterns in the data. 
  • Pie and donut charts: In the case of pie and donut charts, a 1:1 aspect ratio (or a square) is usually the most effective, as it keeps the chart well-proportioned and symmetric. This allows viewers to accurately compare different segments based on their size, such as the market share percentages of popular smartphone brands. 
  • Scatterplots: Scatterplots often benefit from a 4:3 or 1:1 aspect ratio, which helps reduce distortion in the data points and enhances the relationship between the two variables. For example, if you’re analyzing the correlation between a person’s age and income, using a 4:3 or 1:1 scatterplot allows the data to be easily interpreted without distorting the relationship between these two variables. 
  • Geographic maps: When working with geographic maps, use an aspect ratio that accurately reflects the proportions of the depicted geographic area. This ensures that visualizations are not distorted and the information is presented accurately. For instance, if you’re creating a map of the United States, using a 16:9 aspect ratio will provide a suitable representation of the country’s geography.