📈 Charts & Visualization
A chart communicates in seconds what a table of numbers might take minutes to understand. Learn which chart type to use for which situation — and how to build, customize, and clean up charts in Google Sheets.
The most common visualization mistake is choosing the wrong chart type. A bar chart works great for comparing categories — but terrible for showing trends over time. A pie chart with 12 slices is almost always unreadable. This module walks you through each chart type, when to use it, and when to avoid it. You'll build charts from the Module 05 pivot table data.
📈 Line Chart
Connects data points with a line, emphasizing direction and rate of change. Time (dates, months) should always be on the horizontal axis.
🟩 Pie Chart
Shows percentage composition. Best with 2–5 categories. Over 5 slices becomes hard to read. Humans are poor at comparing angles.
🌟 Scatter Plot
Each dot is one data point. X-axis = one variable, Y-axis = another. Shows correlation, clusters, and outliers.
Use the pivot table result from Module 05 (Revenue by Region). The data should look like this:
| A — Region | B — Revenue |
|---|---|
| East | 3840 |
| North | 4643 |
| South | 5245 |
| West | 3515 |
- Select the data range including headers: A1:B5.
- Go to Insert → Chart. A chart is inserted with a Chart editor panel on the right.
- Under "Chart type", select Bar chart (or Column chart — same thing, just orientation).
- Sheets automatically detects your data — Region on one axis, Revenue on the other.
- Click the chart to move or resize it. Drag the corners to resize. Drag the center to move.
Customizing your chart:
- Chart title: In the Chart editor, go to the Customize tab → Chart & axis titles → type "Revenue by Region".
- Axis titles: Under the same section, add a horizontal axis title ("Region") and a vertical axis title ("Revenue ($)").
- Colors: Customize tab → Series → click the color swatch to change bar color. Use your green theme for consistency.
- Legend: Customize → Legend → position it or hide it (for a single-series chart, a legend is often unnecessary).
- Grid lines and background: Customize → Chart style → toggle background color, border, font.
Use the monthly revenue data from the Module 05 time series pivot (or enter this data manually on a new sheet):
| A — Month | B — Revenue |
|---|---|
| January | 4305 |
| February | 3645 |
| March | 2913 |
| April | 4775 |
| May | 2375 |
| June | 3135 |
- Select A1:B7 and go to Insert → Chart.
- Change chart type to Line chart.
- Add a title: "Monthly Revenue Trend — 2024".
- Add axis labels: horizontal = "Month", vertical = "Revenue ($)".
- In Customize → Series, enable "Point size" to make data points visible as dots on the line.
Enter this study data on a new sheet:
| A — Study Hours | B — Test Score |
|---|---|
| 1 | 52 |
| 2 | 58 |
| 3 | 64 |
| 4 | 70 |
| 5 | 75 |
| 6 | 82 |
| 7 | 78 |
| 8 | 88 |
| 9 | 91 |
| 10 | 95 |
- Select A1:B11 → Insert → Chart → choose Scatter chart.
- Add title "Study Hours vs. Test Score".
- Add axis labels: horizontal = "Study Hours", vertical = "Test Score (%)".
- In Customize → Series, you can add a trendline to show the general direction of the relationship.
✅ Do
- Always include a chart title
- Label your axes clearly
- Start the Y-axis at zero for bar charts
- Use consistent colors throughout a report
- Keep it simple — remove clutter
- Use color to highlight, not to decorate
- Choose the right chart type for the data
❌ Don't
- Use 3D charts (they distort perception)
- Use pie charts with more than 5 slices
- Use rainbow colors for no reason
- Truncate the Y-axis to exaggerate differences
- Use gridlines so dark they overwhelm the data
- Skip axis labels and titles
- Use a chart when a table communicates better
Using your Module 05 pivot table data:
- Bar chart: Create a bar chart showing Revenue by Region. Title it appropriately. Add axis labels. Change the bar color to green (#43A047).
- Line chart: Create a line chart showing Monthly Revenue Trend from the time series pivot (or the sample data above). Add a proper title and both axis labels. Enable data point dots on the line.
- Pie chart: Create a pie chart showing Revenue by Category (3 slices: Electronics, Books, Clothing). Notice how easy it is to read with just 3 slices vs. what would happen with 10.
Reflection questions:
- Which region has the highest revenue? Is it easier to see in the bar chart or the data table?
- Is the monthly trend going up, down, or is it mixed?
- What percentage of revenue comes from Electronics?
In 1858, Florence Nightingale — known for nursing, but also a pioneer statistician — created a "rose diagram" (now called a polar area chart) to show British Army mortality data. Her visualization proved that most soldiers were dying from preventable infections, not battle wounds. It convinced the government to reform army hospitals. The chart literally saved lives.
This is why visualization matters: the same data that looked like dry numbers in a table became unmistakable in chart form. Good charts change minds and drive decisions.
- Bar chart: comparing values across categories. Great default choice.
- Line chart: trends over time. Time always goes on the horizontal axis.
- Pie chart: parts of a whole. Use only with 2–5 categories. Avoid 3D.
- Scatter plot: relationship between two numeric variables. Great for showing correlation.
- Every chart needs a title and axis labels — otherwise it's not self-explanatory.
- Start bar chart Y-axes at zero. Truncated axes can make small differences look dramatic.
- Customize via: Insert → Chart → Chart editor → Customize tab.
- A clear chart communicates in seconds. A cluttered chart communicates confusion.