How to Choose the Right Chart (and Avoid the Wrong One)

Introduction

In 2014, the UK government tried to make taxes feel transparent.

They sent out pie charts to over 24 million people. What they didn’t expect?

National backlash.

The charts lumped together diverse programs into one bloated “welfare” slice—igniting confusion and fueling public outrage. The message wasn’t wrong. But the chart buried the truth. (The Guardian)

Bad data visualization doesn’t just look sloppy—it costs trust. And when you lose trust, you lose everything.

Here’s the thing: choosing the right chart isn’t just a design decision. It’s a clarity decision. Done right, charts make insights obvious. Done wrong, they turn your message into mud.

Let’s break down the right chart for the right job—and how to avoid common mistakes that turn insight into noise.

Bar Chart

Bar charts are the boardroom’s favorite weapon—and for good reason. They’re fast, familiar, and great for side-by-side comparisons.

When to Use:

• You’re comparing distinct categories (like region or product)
• You need to show rankings or performance side-by-side
• You want instant visual clarity without explanation

Common Mistakes:

• Using bar charts for continuous data like time—line charts work better
• Showing too many bars—if your chart looks like a picket fence, cut it down
• Forgetting to label axes or align them properly (makes you look sloppy)

Example:

• Comparing ROI by marketing channel after a campaign (email vs. paid vs. organic vs. referral)

Stacked Bar Chart

Stacked bar charts let you show the total and the story inside the total.

Use them to show how the parts contribute—but be careful: too many parts, and the story disappears.

When to Use:

• You want to show the whole and what builds it
• You’re comparing subcategories across several groups
• You want to emphasize total size + relative share

Common Mistakes:

• Stacking too many categories—3–4 max or it turns into soup
• Poor color contrast makes the chart unreadable
• Trying to compare middle segments across bars (nearly impossible)

Example:

• Showing revenue by product line within each region (e.g. North America Q1)

Multi-Bar Chart (Grouped Bar Chart)

Grouped bar charts are your best friend when you want to compare things side by side and across categories.

Unlike stacked bars, these are built to make intra-group differences obvious.

When to Use:

• Comparing multiple items within each group
• Highlighting differences across categories
• You want people to see patterns quickly

Common Mistakes:

• Too many groups or bars—gets messy fast
• Colors that are too similar make it hard to tell what’s what
• Inconsistent spacing throws off visual rhythm

Example:

• Comparing Q2 sales for 3 products across 4 countries

Pie Chart

Pie charts look friendly. That’s the trap.

They’re fine when you’ve got a few categories—but fall apart with complexity.

When to Use:

• Showing 2–5 clear categories
• Emphasizing part-to-whole relationships
• You want to show a single snapshot, not compare trends

Common Mistakes:

• Squeezing in 6+ segments—it becomes unreadable
• Using similar-sized slices—nothing stands out
• Comparing multiple pies side by side (almost always a bad idea)

Example:

• Showing percentage of customer acquisition by source (organic, paid, referral, etc.)

Donut Chart

Donut charts are pie charts with a hole—but that hole is valuable.

It gives you space to add key numbers, like totals or insights.

When to Use:

• You want to show proportions and emphasize a center value
• There are 2–4 categories worth comparing
• You need a cleaner layout than a pie

Common Mistakes:

• Overloading the chart with too many segments
• Ignoring the center—missed opportunity
• Using thick rings that dominate the layout

Example:

• Showing budget allocation by team with total budget in the center

Spider Chart (Radar Chart)

Spider charts (aka radar charts) are great for showing how one thing stacks up across multiple traits.

But don’t overdo it—too many axes and this chart becomes spaghetti.

When to Use:

• Comparing a single item across multiple attributes
• Showing strengths and weaknesses clearly
• Visualizing performance metrics in a compact format

Common Mistakes:

• Using too many dimensions (keep it to 3–7)
• Comparing multiple data sets without color clarity
• Using inconsistent scales across axes

Example:

• Comparing product performance across usability, price, and support

Gantt Chart

Gantt charts aren’t flashy—but they get stuff done.

They help teams align on who’s doing what, by when.

When to Use:

• Planning projects with timelines and dependencies
• Tracking progress and deliverables
• Communicating schedules to stakeholders

Common Mistakes:

• Adding too many tasks or dependencies without grouping
• Confusing timelines or vague dates
• Skipping milestone markers

Example:

• Launch plan showing design, dev, QA, and rollout timelines

Line Chart

If you want to show a trend over time, start here.

Line charts make it easy to see where things are headed.

When to Use:

• Showing change over time
• Comparing continuous metrics
• Highlighting trends across categories

Common Mistakes:

• Using too many lines—chart turns to spaghetti
• Bad axis scaling distorts the story
• Applying it to categories instead of time

Example:

• Year-over-year traffic trends by device type

Area Chart (Multi-Line)

Area charts are like line charts—but they add volume.

Use them when the total matters just as much as the trend.

When to Use:

• Showing how parts contribute to a whole over time
• Comparing trends + total magnitude
• Emphasizing cumulative growth

Common Mistakes:

• Overlapping too many data series
• Using opaque colors (hides context)
• Misinterpreting “stacked” areas as absolute values

Example:

• Visualizing sales contribution by product line over a year

‍

Conclusion and Next Steps

The best visualizations don’t just display data—they tell a story. But storytelling doesn’t mean being clever for the sake of it. It means getting clear—fast.

Start with the question, not the chart. When you know what you're trying to answer, the right visualization becomes obvious. The best charts make insights unavoidable.

Clarity beats cleverness. Every time.

Want more ways to make your data sing? Subscribe to our newsletter for practical tips on building clear, effective design systems—one chart at a time.

‍