Charts are one of the most useful tools in Microsoft Excel because they help transform raw numbers into visual information that is easier to understand. Whether you are working with sales reports, financial data, school projects, analytics dashboards, or business presentations, charts can quickly reveal trends, comparisons, and patterns that may not be obvious inside spreadsheets alone.
However, some datasets contain values with very different scales. For example, one data series may represent revenue in thousands while another represents percentages or small decimal values. Plotting both on the same chart using a single axis often makes one dataset difficult to read because the larger values dominate the chart visually. This is where a secondary axis becomes extremely useful.
A secondary axis allows Excel to display two different measurement scales on the same chart. One axis usually appears on the left side while the secondary axis appears on the right side. This makes it possible to compare different types of data more clearly without distorting the chart.
Microsoft Excel allows users to easily add, customize, and remove secondary axes using built-in chart tools. In this guide, you will learn how to add or remove a secondary axis in Microsoft Excel charts, when to use it, chart types that support it, customization options, and common mistakes users should avoid.
What Is A Secondary Axis In Excel?
A secondary axis is an additional vertical or horizontal measurement scale added to an Excel chart. It allows two different data series to use separate value ranges inside the same chart.
Normally, Excel charts use only one primary axis. All charted values share the same scale. This works well when datasets are similar in size. However, problems appear when comparing data with very different ranges.
For example:
- Revenue: 500,000
- Profit Margin: 12%
If both use the same axis, the percentage line may appear almost flat because the revenue numbers are much larger.
Adding a secondary axis solves this problem by assigning:
- Revenue to the primary axis
- Profit Margin to the secondary axis
This allows both datasets to remain readable and properly scaled.
Secondary axes are commonly used in:
- Financial reports
- Sales dashboards
- Scientific charts
- Business analytics
- Inventory tracking
- Marketing performance reports
Excel usually displays the secondary axis on the right side of the chart automatically.
When To Use A Secondary Axis
Secondary axes are helpful when comparing datasets that use:
- Different units
- Different scales
- Different measurement types
Examples include:
- Revenue vs percentage growth
- Temperature vs rainfall
- Sales vs customer satisfaction
- Website traffic vs conversion rate
- Production volume vs defect percentage
Without a secondary axis, smaller-value datasets often become visually compressed and difficult to interpret.
However, secondary axes should be used carefully. Overusing them can make charts confusing or misleading. If datasets are unrelated or visually overcrowded, separate charts may work better.
Good secondary axis charts should remain:
- Easy to read
- Clearly labeled
- Visually balanced
- Properly titled
Chart Types That Support Secondary Axes
Not every Excel chart type supports secondary axes.
Common supported chart types include:
- Line charts
- Column charts
- Bar charts
- Combo charts
- Area charts
Combo charts are especially popular because they allow different chart styles together. For example:
- Columns for revenue
- Line graph for percentage growth
Pie charts, doughnut charts, and some specialized charts do not support secondary axes because they do not use standard coordinate axes.
Combo charts are often the best option when working with secondary axes because they improve readability significantly.
How To Add A Secondary Axis In Excel
Adding a secondary axis in Excel is relatively simple.
Method 1: Using Chart Design
- Open your Excel spreadsheet
- Select the chart
- Click:
Chart Design - Choose:
Change Chart Type - Select:
Combo
Excel displays available data series.
- Check:
Secondary Axis
beside the data series you want to place on the second axis.
- Click OK
Excel automatically adds the secondary axis to the chart.
The selected series now uses a separate measurement scale displayed on the right side.
Method 2: Using Format Data Series
Another quick method involves formatting a specific data series directly.
- Click the chart
- Select the data series
- Right-click the series
- Choose:
Format Data Series
A formatting panel appears.
- Under:
Series Options - Select:
Secondary Axis
Excel immediately creates the secondary axis.
This method is especially useful for quickly adjusting existing charts without changing chart types.
How To Add A Secondary Horizontal Axis
Although most users add vertical secondary axes, Excel can also create secondary horizontal axes in some chart types.
To enable:
- Select the chart
- Open:
Chart Elements - Choose:
Axes - Enable:
Secondary Horizontal Axis
This feature is less commonly used but may help in advanced scientific or engineering charts.
Using Combo Charts With Secondary Axes
Combo charts work extremely well with secondary axes because they combine multiple chart styles together.
For example:
- Sales displayed as columns
- Profit margin displayed as a line
To create a combo chart:
- Select your data
- Click:
Insert - Choose:
Combo Chart - Assign chart types to each series
- Enable secondary axis for one series
Combo charts improve readability because different chart styles visually separate datasets more effectively.
Microsoft Excel even includes recommended combo chart templates for common business scenarios.
Customizing The Secondary Axis
After adding a secondary axis, users can customize its appearance and scaling.
Common customization options include:
- Minimum values
- Maximum values
- Number formatting
- Axis labels
- Tick marks
- Axis colors
- Font size
- Gridlines
To customize:
- Right-click the secondary axis
- Choose:
Format Axis
The formatting pane allows detailed adjustments.
Users can manually define:
- Fixed ranges
- Percentage formatting
- Currency formatting
- Decimal precision
Proper scaling is important because misleading axis ranges may distort data interpretation visually.
How To Remove A Secondary Axis
Removing a secondary axis is just as simple as adding one.
Method 1: Delete The Axis Directly
- Click the secondary axis
- Press:
Delete
Excel removes the axis instantly.
Method 2: Change Data Series Back To Primary Axis
- Right-click the data series
- Select:
Format Data Series - Choose:
Primary Axis
The secondary axis disappears automatically if no series uses it.
This method preserves chart formatting more cleanly.
Common Problems With Secondary Axes
Users sometimes experience issues while working with secondary axes.
Chart Looks Confusing
Too many data series may overcrowd the chart visually.
Solution:
- Simplify chart design
- Use fewer datasets
- Separate unrelated data
Incorrect Scaling
Automatic scaling sometimes creates misleading visuals.
Solution:
- Adjust minimum and maximum values manually
Axis Labels Overlap
Large charts or long labels may create clutter.
Solution:
- Resize chart
- Rotate labels
- Reduce font size
Secondary Axis Missing
Some chart types do not support secondary axes.
Solution:
- Switch to combo, line, or column charts
Best Practices For Secondary Axis Charts
Good chart design improves readability and prevents confusion.
Recommended practices include:
- Use only when necessary
- Label axes clearly
- Use contrasting chart colors
- Avoid too many datasets
- Keep chart titles descriptive
- Match chart styles logically
For example:
- Bars for volume
- Lines for percentages
This improves visual interpretation immediately.
Users should also avoid manipulating axis scales in misleading ways that exaggerate trends artificially.
Real-World Examples Of Secondary Axis Usage
Secondary axes are commonly used in business, finance, and analytics.
Financial Reports
- Revenue on primary axis
- Profit margin on secondary axis
Marketing Dashboards
- Website visitors
- Conversion rate percentages
Weather Charts
- Rainfall totals
- Temperature readings
Inventory Management
- Stock quantity
- Defect percentage
School Projects
- Population growth
- Birth rate percentages
These combinations help visualize relationships between different types of measurements more effectively.
Secondary Axis In Different Excel Versions
The process for adding secondary axes remains similar across:
- Excel 2016
- Excel 2019
- Excel 2021
- Microsoft 365
However, interface layouts may vary slightly depending on the version.
Modern Excel versions provide:
- Improved combo charts
- Easier formatting tools
- Recommended chart suggestions
Microsoft 365 versions often include the most streamlined chart editing experience.
Tips For Better Excel Charts
Helpful charting habits include:
- Keep charts simple
- Avoid unnecessary effects
- Use readable fonts
- Label data properly
- Use legends carefully
- Maintain clean spacing
Charts should communicate information quickly without overwhelming viewers.
Secondary axes are powerful tools, but simplicity often improves understanding more than excessive complexity.
Final Thoughts
Secondary axes in Microsoft Excel are extremely useful for comparing datasets with different scales, units, or measurement types inside a single chart. They help improve readability and allow users to visualize relationships between values that would otherwise appear distorted on a standard chart.
Excel makes it easy to add or remove secondary axes using combo charts, formatting tools, and chart design options. Users can also customize axis scaling, formatting, and appearance to create cleaner and more professional-looking charts.
However, secondary axes should be used carefully. Overcomplicated charts can confuse readers instead of helping them understand data. Keeping charts simple, properly labeled, and visually balanced ensures that information remains clear and effective.
Whether creating financial dashboards, sales reports, analytics charts, scientific graphs, or business presentations, understanding how to manage secondary axes is an important Excel skill that improves data visualization significantly.
FAQs
What is a secondary axis in Excel?
A secondary axis is an additional chart axis used to display data series with different value ranges or measurement types.
How do I add a secondary axis in Excel?
Right-click a data series, select “Format Data Series,” and choose “Secondary Axis.”
Why should I use a secondary axis?
Secondary axes help compare datasets with different scales more clearly inside the same chart.
Which chart types support secondary axes?
Line charts, column charts, bar charts, area charts, and combo charts commonly support secondary axes.
How do I remove a secondary axis in Excel?
Select the secondary axis and press Delete, or move the data series back to the primary axis.
