You made a chart. You double-checked the data. But something about it just looks... off.
Maybe the bars are crammed together. Maybe the line looks flat when you expected a spike. Maybe your pie chart has 17 slices and nobody can tell them apart.
You're not imagining it. Bad-looking charts are incredibly common—and the causes are almost always the same handful of mistakes.
According to data visualization researcher Edward Tufte, the vast majority of chart problems come from poor design choices, not bad data. The data is fine. The chart is lying about it.
In this guide, you'll learn the 9 most common reasons charts look wrong—and exactly how to fix each one.
Problem #1: Truncated Y-Axis
What It Looks Like
Your bar chart makes a small difference look enormous. A 2% change looks like a 200% change.
Why It Happens
The Y-axis doesn't start at zero. Excel and many tools auto-scale axes to fill space, which can start the Y-axis at, say, 95 instead of 0.
Why It's a Problem
This is one of the most common ways charts mislead. Quartz documented dozens of misleading charts in major publications, and truncated axes were the #1 offender. A bar that appears twice as tall as another bar should represent twice the value—not 52 vs 48.
The Fix
- Bar charts: Always start the Y-axis at zero. No exceptions.
- Line charts: Starting above zero is acceptable (since line charts show trends, not absolute comparison), but label the axis clearly.
- If the difference is genuinely small: Use a different chart type or call out the percentage change in an annotation.
Rule of thumb: If hiding the Y-axis labels changes the viewer's interpretation, the axis is misleading.
Problem #2: Wrong Chart Type
What It Looks Like
The chart technically shows the data, but it's hard to read or interpret. Patterns are hidden instead of revealed.
Common Mismatches
| Data Type | Wrong Chart | Right Chart |
|---|---|---|
| Trends over time | Bar chart | Line chart |
| Category comparison | Pie chart (12+ slices) | Bar chart |
| Parts of a whole (5-7 items) | Stacked bar chart | Pie chart |
| Correlation between variables | Two separate bar charts | Scatter plot |
| Distribution of values | Bar chart of raw values | Histogram |
| Step-by-step financial breakdown | Bar chart (separate bars) | Waterfall chart |
The Fix
Ask yourself: "What question is this chart answering?"
- "How does X change over time?" → Line chart
- "How does A compare to B?" → Bar chart
- "What share does each category have?" → Pie chart (if 7 or fewer categories)
- "Are X and Y related?" → Scatter plot
- "How did we get from starting value to ending value?" → Waterfall chart
For a complete decision guide, read our 7 chart types explained article. If you're just getting started, our data visualization for beginners guide covers the fundamentals.
Problem #3: Too Many Data Points
What It Looks Like
A bar chart with 40 bars. A line chart with 15 overlapping lines. A pie chart with 20 slices. The viewer can't extract any useful insight.
Why It Happens
You have lots of data and want to show all of it. But showing everything means communicating nothing—the signal drowns in noise.
The Fix
- Bar chart with too many bars: Show top 10, group the rest into "Other." Sort by value (largest first).
- Line chart with too many lines: Highlight the 2-3 most important. Gray out the rest as context. Or use small multiples (one mini-chart per line).
- Pie chart with too many slices: Maximum 5-7 slices. If more, switch to a horizontal bar chart.
- Scatter plot with too many points: Use transparency (alpha=0.3) so overlapping points are visible, or use a heatmap/density plot.
Golden rule: Every element in your chart should earn its place. If removing it doesn't reduce understanding, remove it.
Problem #4: Poor Color Choices
What It Looks Like
Colors clash, don't contrast enough, or confuse rather than clarify. Common symptoms:
- Red and green bars side by side (invisible to 8% of males who are colorblind)
- 10 different bright colors with no logic
- Pastel colors that disappear when projected
- Rainbow gradient that implies false hierarchy
The Fix
- Use 2-3 colors maximum. One main color for data, one accent color for emphasis, gray for context.
- Use colorblind-safe palettes. Blue/orange is safe for nearly all types of color vision deficiency. Avoid red/green combinations.
- Test in grayscale. Print your chart in black and white. Can you still distinguish categories? If not, add patterns or labels.
- Colors should mean something. Red = negative, green = positive, gray = baseline. Don't assign colors randomly.
For a deep dive, read our guide to color in data visualization, our color palette recommendations, and our colorblind-friendly chart guide.
The ColorBrewer tool by Cynthia Brewer is an excellent free resource for choosing accessible palettes.
Problem #5: Visual Clutter
What It Looks Like
Heavy gridlines, thick borders, 3D effects, gradients, drop shadows, background images, unnecessary legend, decorative clip art. The chart looks busy but communicates little.
Why It Happens
Default settings in Excel and many tools add heavy gridlines and borders. Users then add more decoration thinking it looks "professional."
The Fix
Follow Edward Tufte's "data-ink ratio" principle: maximize the ink used for data, minimize everything else.
Remove:
- Heavy gridlines (or make them very light gray)
- Chart borders
- 3D effects (always)
- Background colors or images
- Redundant labels (if the axis label says "Revenue ($M)", you don't need "$4M" on every bar)
- Legend, if labels can go directly on the data
Keep:
- The data itself (bars, lines, points)
- Axis labels with units
- Chart title
- Direct data labels (if space permits)
Result: A clean chart where the data is the star, not the decoration. For more on this, see Dark Horse Analytics' "Data Looks Better Naked" series.
Problem #6: Misleading Scale
What It Looks Like
Two data series on the same chart with wildly different scales. One line goes from 0-100, another from 0-10,000,000. The smaller series looks flat.
Why It Happens
Plotting revenue ($millions) and customer count (hundreds) on the same Y-axis. The customer count line hugs the bottom of the chart and looks meaningless.
The Fix
- Option A: Dual Y-axis. Put one series on the left axis, one on the right. Label each clearly. But be cautious—dual axes can confuse readers.
- Option B: Two separate charts. Stack them vertically with aligned X-axes. Clearer comparison without scale confusion.
- Option C: Normalize the data. Convert both to percentages (e.g., % change from baseline). Now both are on the same scale.
- Option D: Index to 100. Set a base period = 100, show all series relative to that. Common in finance and economics.
See our time series charts guide for techniques on handling multi-scale temporal data.
Problem #7: No Context or Labels
What It Looks Like
A chart with no title, no axis labels, no units. What does the Y-axis represent? What time period? What's the source?
Why It's a Problem
A chart without context is meaningless. The viewer is left guessing: Is this revenue or profit? Dollars or euros? Monthly or annual? The Data Journalism Handbook emphasizes that every chart should be self-explanatory—a reader should understand it without reading surrounding text.
The Fix
Every chart needs:
- Title: Descriptive, not generic. "Q4 Revenue by Region" not "Chart 1." Better: "West Region Drove 45% of Q4 Revenue Growth."
- Axis labels: Include units. "Revenue (USD millions)" not "Revenue." "Time (months)" not just dates.
- Source: Where did the data come from? "Source: Company Q4 earnings report, 2025."
- Date/period: What time frame? "January-December 2025."
For academic contexts, see our publication-ready charts guide. For business settings, read our business reports with charts guide.
Problem #8: Distorted Proportions (3D Effects)
What It Looks Like
A 3D pie chart where the front slice looks enormous and the back slice looks tiny—even though they represent similar values. Or a 3D bar chart where perspective makes accurate comparison impossible.
Why It's a Problem
3D effects distort visual proportions. In a 3D pie chart, slices closer to the viewer appear larger. In a 3D bar chart, the angle makes it impossible to judge exact heights. Research by Few (2007) shows that 3D charts consistently lead to misinterpretation of values.
The Fix
Never use 3D charts. Period. There is no data visualization scenario where a 3D effect improves comprehension. Every serious practitioner—Tufte, Few, Cairo, Knaflic—agrees on this.
- 3D pie chart → Flat pie chart, donut chart, or bar chart
- 3D bar chart → Flat bar chart
- 3D line chart → Flat line chart
Tools like CleanChart don't even offer 3D options—by design. Modern chart tools default to clean 2D charts because they communicate better.
Problem #9: The Data Itself Is the Problem
What It Looks Like
The chart renders correctly, but the pattern doesn't match what you expected. The trend line is erratic. The bars are all different heights when they should be similar. Outliers dominate the picture.
Why It Happens
Sometimes the chart is fine—it's the data that needs attention:
- Duplicate rows inflating totals
- Missing values creating gaps
- Outliers skewing averages
- Inconsistent formats (dates in multiple formats, mixed units)
- Wrong aggregation (summing when you should be averaging)
The Fix
Clean your data before charting.
- Check for duplicates
- Handle missing values
- Standardize formats
- Identify and investigate outliers
- Verify your calculations
Read our complete guide to cleaning CSV data for a step-by-step process. Also check out common data cleaning mistakes so you know what to watch for.
CleanChart automatically detects many of these problems when you upload your data—flagging duplicates, missing values, and format inconsistencies before you even create a chart.
Quick Diagnosis: What's Wrong With My Chart?
Use this table to quickly identify and fix your chart problem:
| Symptom | Likely Problem | Fix |
|---|---|---|
| Small differences look huge | Truncated Y-axis | Start axis at zero (bar charts) |
| Hard to read, patterns unclear | Wrong chart type | Match chart to data type |
| Too busy, can't focus | Too many data points | Top 10 + "Other" group |
| Colors clash or confuse | Poor color choices | Use accessible palettes |
| Looks amateurish | Visual clutter (3D, gridlines) | Remove decoration, go 2D |
| One series looks flat | Mismatched scales | Dual axis or separate charts |
| Viewer is confused | Missing labels/context | Add title, axis labels, source |
| Proportions look off | 3D distortion | Switch to 2D. Always. |
| Data doesn't match expectations | Dirty data | Clean data first |
Before-You-Publish Checklist
Run through this list before sharing any chart:
- Y-axis: Does it start at zero? (Required for bar charts)
- Chart type: Does it match my message? (Reference guide)
- Data points: Can I distinguish all categories? (Max 7 for pie, 10-15 for bar)
- Colors: Are they accessible and meaningful? (Colorblind-safe?)
- Clutter: Have I removed gridlines, borders, 3D effects?
- Scale: Are all series comparable?
- Labels: Title, axis labels with units, source?
- 3D: Is it 2D? (Must be yes)
- Data: Clean, no duplicates, no missing values?
- The 5-second test: Can someone understand the main point within 5 seconds?
Frequently Asked Questions
Should I always start the Y-axis at zero?
Bar charts: Yes, always. Bar charts encode data as length. If you don't start at zero, the lengths are misleading.
Line charts: Not necessarily. Line charts encode data as position and slope. Starting above zero to zoom in on a trend is often acceptable—just label the axis clearly and don't mislead.
Scatter plots: Rarely. Axes should fit the data range. Starting at zero often wastes space.
Are pie charts ever the right choice?
Yes, but only when:
- You're showing parts of a whole (percentages that add to 100%)
- You have 5-7 categories maximum
- The differences between slices are large enough to see
If you have more than 7 categories or the differences are subtle, use a bar chart instead. See our pie chart maker page for best practices.
How do I make my chart accessible?
Three essentials:
- Don't rely on color alone. Use patterns, labels, or annotations alongside color.
- Use colorblind-safe palettes. Blue/orange is universally safe. Avoid red/green.
- Include alt text if embedding in web pages or documents.
Full guide: Creating Accessible Colorblind-Friendly Charts.
My boss wants 3D charts. What do I do?
Show them the same data in 2D and 3D side by side. The 2D version is always clearer. Frame it as "I want to make sure the numbers come through accurately." If they insist, choose a mild 3D angle with no rotation, and add data labels to every element so the exact values are visible despite the distortion.
What's the best free tool for avoiding these mistakes?
CleanChart is designed to prevent most of these problems by default. It starts axes at zero for bar charts, uses clean 2D designs, applies colorblind-safe palettes, and auto-cleans data on import. Our best free chart makers comparison covers the alternatives.
Charts That Look Right, Every Time
Upload your data and get clean, professional charts. No 3D. No clutter. No guessing.
Try CleanChart FreeRelated Articles
- 7 Chart Types Explained with Examples
- The Role of Color in Data Visualization
- Creating Accessible Colorblind-Friendly Charts
- Best Color Palettes for Data Visualization
- Complete Guide to Cleaning CSV Data
- Common Data Cleaning Mistakes
Quick Tools
- Bar Chart Maker - Clean 2D bar charts
- Line Chart Maker - Trend visualization
- Pie Chart Maker - Parts-of-a-whole charts
- Donut Chart Maker - Pie chart alternative
- Scatter Chart Maker - Correlation analysis
- CSV to Bar Chart - Convert your data
- Excel to Bar Chart - Import Excel files
External Resources
- Edward Tufte - The pioneer of data-ink ratio and chart design principles
- ColorBrewer - Free tool for choosing accessible color palettes
- Dark Horse Analytics: Data Looks Better Naked - Visual guide to removing chart clutter
- Quartz: Misleading Charts - Real-world examples of chart mistakes
- Data Journalism Handbook - Best practices for data communication
- Storytelling with Data - Cole Nussbaumer Knaflic on effective chart design
Last updated: January 29, 2026