Bar Chart

A bar chart represents data using rectangular bars, where the length or height of each bar corresponds to the value it encodes. Each bar represents a distinct category, making differences between them immediately visible.

Bar charts excel at comparing discrete categories and highlighting differences between them.

An example of an embedded bar chart

Creating an Effective Bar Chart

Recommended data types for each axis:

X-Axis Dates or categorical data
Y-Axis Numerical values

Description

Bars - each bar represents one category; bar length encodes the value
X-Axis - lists the categories being compared
Y-Axis - represents the measured quantity, starting at zero
Colors - a single color is typical; multiple colors can highlight specific bars

When to Use a Bar Chart

Compare values across categories - bar length makes magnitude differences intuitive at a glance
Show changes over time - when time periods are discrete (months, quarters, years), bars work well
Rank items - sorting bars from tallest to shortest immediately surfaces the top and bottom performers
Display frequency distributions - show how often each category occurs

When to Avoid a Bar Chart

Continuous trends - use a line chart when the X-axis is a continuous time series
Part-to-whole relationships - use a pie chart or stacked bar chart when proportions are the story
Two or more breakdown categories - use a grouped bar chart or stacked bar chart for multi-series data
Correlations between two numeric variables - use a scatterplot

Variants

Waterfall Chart

A waterfall chart is a bar chart variant where each bar starts where the previous one ended, visualizing a running cumulative total. It is ideal for showing how a starting value is affected by a series of positive and negative contributions - for example, a profit-and-loss breakdown or a budget reconciliation.