How do I set the figure title and axes labels font size?

python

matplotlib

font-size

customization

byAnton Shumikhin·Jan 21, 2025

To alter text size in your matplotlib plot, utilize the fontsize attribute in title, xlabel, and ylabel:

import matplotlib.pyplot as plt

# Sample data
plt.plot([1, 2, 3], [4, 5, 6])

# Apply font sizes (because size does matter!)
plt.title('Your Title', fontsize=20)
plt.xlabel('X Axis', fontsize=14)
plt.ylabel('Y Axis', fontsize=14)

plt.show()

You can modify fontsize=20 for the title and fontsize=14 for axis labels as per your requirement.

Mastering Fine Typography

For enhanced customization of fonts on different elements, use the fontdict parameter like a typography maestro:

plt.title('Elegant Title', fontdict={'fontsize': 20, 'fontweight': 'bold'})  # Bold and beautiful!
plt.xlabel('Measured Parameters', fontdict={'fontsize': 14, 'fontstyle': 'italic'})  # Elegance personified!
plt.ylabel('Values', fontdict={'fontsize': 14, 'color': 'green'})  # Green for go!

Global and Local Settings: Protocol Decoded

To maintain a uniform look across various plots, matplotlib.rcParams can establish global defaults:

import matplotlib as mpl

mpl.rcParams['axes.titlesize'] = 20  # For title size that speaks volumes
mpl.rcParams['axes.labelsize'] = 14  # For axes labels that play a supporting role

Use local settings to enforce a certain style, and prevent unintended global mutations.

Dynamically Adjusting Font Size

Circumstances often dictate dynamic changes to font sizes:

While resizing plots, enlarged fonts preserve legibility.
Scaling fonts with dimensions of images is paramount when creating visualizations for publication or presentations.

After tweaking font sizes, plt.draw() fetches a refreshed display.

Journal of Readability: Guidelines

Legend labels should be noticeably smaller than axes labels.
Legends can match the size of axes labels or can be a bit smaller.
While annotations matter, they should not upstage the main characters – the axes labels and title.

explain-codes / Python / How do I set the figure title and axes labels font size?

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