Pie charts

Matplotlib Basics

2 min read

Published Oct 5 2025

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A pie chart divides a circle into wedges (slices), where each slice’s size represents its proportion of the total. It’s ideal for showing relative percentages or part-to-whole relationships.


Syntax:

plt.pie(x, labels=None, colors=None, autopct=None, startangle=None, shadow=False, explode=None, counterclock=True)

Parameters:

  • x = Data values (list, array, or Series)
  • labels = Names for each wedge
  • colors = Slice colours
  • autopct = Format string to display % values
  • startangle = Rotation of the start angle (degrees)
  • shadow = Adds a drop shadow
  • explode = Offsets slices outward
  • counterclock = If True, slices are drawn counterclockwise
  • labeldistance, pctdistance = Control label and % text distance



Basic example

import matplotlib.pyplot as plt

sizes = [30, 45, 15, 10]
labels = ['Apples', 'Bananas', 'Cherries', 'Dates']

plt.pie(sizes, labels=labels)
plt.title("Basic Pie Chart")
plt.show()

matplotlib pie chart basic example




Add percentage labels

import matplotlib.pyplot as plt

sizes = [30, 45, 15, 10]
labels = ['Apples', 'Bananas', 'Cherries', 'Dates']

plt.pie(sizes, labels=labels, autopct='%1.1f%%')
plt.title("Pie Chart with Percentages")
plt.show()

%1.1f%% → 1 decimal place percentage (e.g., 45.3%)


matplotlib pie chart percentage labels example




Customise colours

You can use named colours, hex codes, or colour maps.

import matplotlib.pyplot as plt

sizes = [30, 45, 15, 10]
labels = ['Apples', 'Bananas', 'Cherries', 'Dates']
colors = ['#ff9999','#66b3ff','#99ff99','#ffcc99']

plt.pie(sizes, labels=labels, colors=colors, autopct='%1.1f%%')
plt.title("Custom Colours")
plt.show()

matplotlib pie chart custom colours example




Explode (offset) a slice

Use explode to “pop out” one or more slices for emphasis:

import matplotlib.pyplot as plt

sizes = [30, 45, 15, 10]
labels = ['Apples', 'Bananas', 'Cherries', 'Dates']

# Explode the first slice (Apples)
explode = [0.1, 0, 0, 0]

plt.pie(sizes, labels=labels, explode=explode, autopct='%1.1f%%')
plt.title("Pie Chart with Exploded Slice")
plt.show()

matplotlib pie chart explode slices example




Start Angle and Direction

  • Use startangle to rotate the pie.
  • Use counterclock=False to reverse direction.
import matplotlib.pyplot as plt

sizes = [30, 45, 15, 10]
labels = ['Apples', 'Bananas', 'Cherries', 'Dates']

plt.pie(sizes, labels=labels, autopct='%1.1f%%', startangle=90, counterclock=False)
plt.title("Rotated Pie Chart")
plt.show()

matplotlib pie chart rotated example




Add shadows

import matplotlib.pyplot as plt

sizes = [30, 45, 15, 10]
labels = ['Apples', 'Bananas', 'Cherries', 'Dates']

plt.pie(sizes, labels=labels, autopct='%1.1f%%', shadow=True)
plt.title("Pie Chart with Shadow")
plt.show()

matplotlib pie chart shadow example




Label and percentage distance

import matplotlib.pyplot as plt

sizes = [30, 45, 15, 10]
labels = ['Apples', 'Bananas', 'Cherries', 'Dates']

plt.pie(
    sizes, labels=labels, autopct='%1.1f%%',
    labeldistance=1.1, pctdistance=0.8
)
plt.title("Adjust Label Distances")
plt.show()

  • labeldistance → distance of labels from centre
  • pctdistance → distance of percentage text from centre

matplotlib pie chart label distance example




Doughnut (ring) chart

A doughnut chart is just a pie chart with a “hole” cut out using wedgeprops:

import matplotlib.pyplot as plt

sizes = [30, 45, 15, 10]
labels = ['Apples', 'Bananas', 'Cherries', 'Dates']

plt.pie(sizes, labels=labels, autopct='%1.1f%%', wedgeprops={'width': 0.5})
plt.title("Doughnut Chart")
plt.show()

You can even nest multiple rings (multi-level doughnut charts) using multiple plt.pie() calls.


matplotlib pie chart doughnut example




Multiple (nested) pies example

import matplotlib.pyplot as plt

group_sizes = [60, 30, 10]
subgroup_sizes = [35, 25, 20, 10, 10]

# Outer ring
plt.pie(group_sizes, radius=1, labels=['A','B','C'], wedgeprops=dict(width=0.3, edgecolor='w'))

# Inner ring
plt.pie(subgroup_sizes, radius=0.7, wedgeprops=dict(width=0.3, edgecolor='w'))

plt.title("Nested Doughnut Chart")
plt.show()

matplotlib pie chart nested doughnut example
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