Change Font Size in Matplotlib

Last Updated : 23 Jul, 2025

Matplotlib library is mainly used to create 2-dimensional graphs and plots. It has a module named Pyplot which makes things easy for plotting. To change the font size in Matplotlib, the two methods given below can be used with appropriate parameters:

Change Font Size using fontsize

You can set the font size argument, figsize change how Matplotlib treats fonts in general, or even change the figure size.

Python3

import matplotlib.pyplot as plt

# setting font sizeto 30
fig, plt = plt.subplots(figsize=(10, 6))

x = [1, 2, 3, 4, 5, 6]
y = [0, 2, 4, 6, 8, 10]

# plotting a plot
plt.plot(x, y)

plt.set_title('Title', fontsize=20)
plt.set_xlabel('Time', fontsize=16)
plt.set_ylabel('Intensity', fontsize=16)

Output:

Change Font Size in Matplotlib rcParams.update()

The rcParams is an instance of the Matplotlib library for handling default Matplotlib values hence to change the default font size we just have to pass the value to the key font.size.

Python3

import matplotlib.pyplot as plt

# setting font sizeto 30
plt.rcParams.update({'font.size': 30})

x = [1, 2, 3, 4, 5, 6]
y = [0, 2, 4, 6, 8, 10]

# plotting a plot
plt.plot(x, y)

# setting title name
plt.title("Title")

# setting x axis label
plt.xlabel("x axis")

# setting y axis label
plt.ylabel("y axis")

plt.show()

Output:

Change Font Size in Matplotlib rc(group, **kwargs)

This function sets the current rc params. The group is the grouping for the rc like line, font, axes, etc and kwargs is a dictionary attribute name and value pairs.

Python3

import matplotlib.pyplot as plt


# creating a dictionary
font = {'size': 10}

# using rc function
plt.rc('font', **font)

x = [1, 2, 3, 4, 5, 6]
y = [0, 2, 4, 6, 8, 10]

# plotting a plot
plt.plot(x, y)

# setting title name
plt.title("Title")

# setting x axis label
plt.xlabel("x axis")

# setting y axis label
plt.ylabel("y axis")

plt.show()