How To Change Font Of Legend In Plot R

R Programming

Changing the font of a legend in a plot in R may seem like a minor detail, but it can make a significant impact on the overall aesthetics of your visualization. As a data scientist, I’ve learned that paying attention to these small design elements can elevate the quality of your work and make it more visually appealing. In this article, I’ll guide you through the process of changing the font of a legend in a plot in R, sharing my personal insights and tips along the way.

Getting Started

First and foremost, it’s important to have a clear understanding of the plot you’re working with. Whether it’s a simple scatter plot, a bar chart, or a complex multi-layered visualization, the process of changing the font of the legend remains consistent.

Step 1: Creating a Basic Plot

To begin, let’s create a basic scatter plot using the built-in mtcars dataset. We’ll use the ggplot2 package, known for its flexibility and powerful features. If you haven’t already installed the package, you can do so by running the command install.packages("ggplot2").

ggplot(data = mtcars, aes(x = wt, y = mpg, color = factor(cyl))) +
geom_point() +
labs(title = "Miles per Gallon vs. Weight", x = "Weight", y = "Miles per Gallon", color = "Cylinders") +
theme(legend.text = element_text(size = 12, family = "Times", face = "italic"))

Understanding the Code

In the above code, we create a scatter plot that compares miles per gallon with weight, color-coding the points by the number of cylinders. The theme function allows us to modify the legend’s font properties. By setting the size, family, and face parameters within element_text, we can control the font size, family, and style of the legend text.

Step 2: Customizing Font Properties

The element_text function within the theme allows for granular control over the text elements in a plot. This applies not only to legends, but also to axis labels, titles, and other text components. By specifiying the family parameter, we can specify the font family, which can include system fonts or imported custom fonts. Additionally, the size parameter lets us define the font size, ensuring optimal readability.


In conclusion, customizing the font of a legend in an R plot is an effective way to enhance the visual appeal of your visualizations. Paying attention to these design details can set your work apart and make it more engaging for your audience. By following the steps outlined in this article, and experimenting with different font families and sizes, you can effectively tailor the legend to best suit your specific visualization needs.