Common Chart Types & When to Use Them

Introduction

The biggest mistake in data visualization is choosing the wrong chart for your data. A beautiful chart is useless if it misrepresents the underlying numbers or confuses the reader.

This guide breaks down the five core chart types available in our free chart generator, explaining exactly how and when to use them.

1. The Bar Chart (or Column Chart)

The Bar Chart is the undisputed king of data visualization. It is the easiest chart for the human brain to process because we naturally judge length and height with high accuracy.

When to use it:

• Comparing categories: e.g., Sales by Region (North, South, East, West).
• Ranking data: Sorting from highest to lowest makes finding the top performer instant.
• Showing changes over time (discrete): e.g., Total Revenue grouped by Year.

Best Practices:

Always start the Y-Axis at 0. If you have long category names (like "Customer Support Escalation Team"), use a horizontal bar chart so the text doesn't overlap.

2. The Line Chart

Line charts connect discrete data points with a continuous line. They imply a relationship between the points, specifically the passage of time.

When to use it:

• Continuous data over time: e.g., Daily website visitors over a 30-day period.
• Spotting trends and volatility: A steep slope instantly communicates rapid growth or decline.
• Comparing multiple series: Plotting "Product A Sales" vs "Product B Sales" on the same timeline.

Best Practices:

Don't crowd the chart with too many lines. If you have more than 5 intersecting lines, it becomes a "spaghetti chart." Filter the data in your dashboard to show only the top performers.

3. The Pie Chart

The Pie Chart is the most heavily debated visualization in the data community. Because humans are bad at judging angles and area, it's often misused.

When to use it:

• Showing composition (Parts of a whole): e.g., Market share breakdown (Apple vs Samsung vs Google).
• When you have 2 to 4 categories maximum.

Best Practices:

The total must always equal 100%. Never use a 3D pie chart (it distorts the areas). If multiple slices are roughly the same size (e.g., 24% vs 26%), use a Bar Chart instead—the difference will be much easier to see.

4. The Area Chart

An area chart is essentially a line chart with the space below the line filled in with color.

When to use it:

• Showing volume or magnitude over time: e.g., Total cumulative revenue over a year.
• Stacked Area: Showing how different categories contribute to a total trend over time (e.g., Total Support Tickets over time, broken down by channel: Phone, Email, Chat).

Best Practices:

Like pie charts, stacked area charts can be hard to read if there are too many categories (the areas in the middle get distorted by the bumps underneath them). Keep categories limited.

5. The Scatter Plot

Scatter plots use a Cartesian grid to plot two numerical variables against each other to see if there is a relationship.

When to use it:

• Finding Correlations: e.g., Plotting "Advertising Spend" (X-Axis) vs "Units Sold" (Y-Axis). If the dots form a line pointing up and to the right, you have a positive correlation.
• Identifying Outliers: If 99 dots are clustered together and 1 dot is entirely separated, you've found an anomaly worth investigating.

Best Practices:

Scatter plots require a lot of data points to be effective. Ensure you use semi-transparent dots on your data reports so you can see where clusters of data overlap heavily.

Frequently Asked Questions