How to Change Font Sizes on a Matplotlib Plot

Often you may want to change the font sizes of various elements on a Matplotlib plot. Fortunately this is easy to do using the following code:

import matplotlib.pyplot as plt

plt.rc('font', size=10) #controls default text size
plt.rc('axes', titlesize=10) #fontsize of the title
plt.rc('axes', labelsize=10) #fontsize of the x and y labels
plt.rc('xtick', labelsize=10) #fontsize of the x tick labels
plt.rc('ytick', labelsize=10) #fontsize of the y tick labels
plt.rc('legend', fontsize=10) #fontsize of the legend

The following examples illustrates how to change the font sizes of various elements in the following matplotlib scatterplot:

import matplotlib.pyplot as plt

x = [3, 4, 6, 7, 8]
y = [12, 14, 15, 19, 24]

plt.scatter(x, y)
plt.title('title')
plt.xlabel('x_label')
plt.ylabel('y_label')
plt.show()

Note: The default font size for all elements is 10.

Example 1: Change the Font Size of All Elements

The following code shows how to change the font size of every element in the plot:

#set font of all elements to size 15
plt.rc('font', size=15) 

#create plot
plt.scatter(x, y)
plt.title('title')
plt.xlabel('x_label')
plt.ylabel('y_label')
plt.show()

Example 2: Change the Font Size of the Title

The following code shows how to change the font size of the title of the plot:

#set title font to size 50
plt.rc('axes', titlesize=50) 

#create plot
plt.scatter(x, y)
plt.title('title')
plt.xlabel('x_label')
plt.ylabel('y_label')
plt.show()

Example 3: Change the Font Size of the Axes Labels

The following code shows how to change the font size of the axes labels of the plot:

#set axes labels font to size 20
plt.rc('axes', labelsize=20) 

#create plot
plt.scatter(x, y)
plt.title('title')
plt.xlabel('x_label')
plt.ylabel('y_label')
plt.show()

Example 4: Change the Font Size of the Tick Labels

The following code shows how to change the font size of the tick labels of the plot:

#set tick labels font to size 20
plt.rc('xtick', labelsize=20) 
plt.rc('ytick', labelsize=20) 

#create plot
plt.scatter(x, y)
plt.title('title')
plt.xlabel('x_label')
plt.ylabel('y_label')
plt.show()

Bonus: Restore the Default Font Sizes

You can use the following code to restore all fonts to their default size at any point:

plt.rcParams.update(plt.rcParamsDefault)

You can find more Matplotlib tutorials here.