How to add a second vertical axis in Excel

A second vertical axis (also called a secondary Y-axis) lets you plot two data series with different scales on the same chart. This is useful when your data ranges are far apart — for example, plotting monthly revenue in the thousands alongside customer count in the hundreds on one chart. Excel handles this through the chart formatting menu, and the process takes about two minutes once you know where to look.

The basic approach is to create your chart with both data series first, then right-click one series and change it to use a secondary axis. The secondary axis appears on the right side of the chart with its own scale, while the primary axis stays on the left.

Key Takeaways

  • Select both data series before creating your chart, or add the second series after by right-clicking the chart and choosing Select Data.
  • Right-click the data series you want on the secondary axis, select Format Data Series, and choose Secondary Axis from the Series Options tab.
  • The secondary axis appears automatically on the right side of the chart with its own scale and gridlines.
  • You can format each axis independently — change colors, labels, and number formats separately for the primary and secondary axes.
  • Column and bar charts work best with secondary axes; line and scatter charts also work but may overlap visually.

Setting up your data before creating the chart

Arrange your data in adjacent columns, with headers in the first row. Put the category labels (like months or product names) in the first column, then your first data series in the second column and your second data series in the third column. For example: Column A contains months (January, February, March), Column B contains revenue figures, and Column C contains customer counts.

Select all three columns including headers. Then go to the Insert tab and choose a chart type — Column, Bar, Line, or Area charts all work with secondary axes. Excel will create a chart with both series plotted against the same scale, which is the starting point you need.

Moving one data series to the secondary axis

Once your chart exists, click on the chart to select it. Then click directly on the data series you want to move to the secondary axis — this is the line, bars, or columns representing one of your two data sets. You should see small squares appear on each data point when you've selected the right series.

Right-click the selected series and choose Format Data Series from the menu. In the panel that opens on the right side of the screen, click the Series Options tab (it looks like a bar chart icon). Look for the option labeled "Plot Series On" and select Secondary Axis. The chart updates immediately — your selected series moves to the right side and gets its own scale.

Understanding what changed on your chart

After you move a series to the secondary axis, you'll see a second Y-axis label appear on the right edge of the chart. This axis has its own scale, independent of the left axis. If your revenue numbers range from 0 to 50,000 and your customer counts range from 0 to 500, the left axis might show 0, 10000, 20000, 30000, 40000, 50000 while the right axis shows 0, 100, 200, 300, 400, 500.

The chart legend now shows both series with different colors or patterns. Gridlines may appear for both axes, though you can turn these off individually if they make the chart hard to read. The two data series are now visually comparable even though their actual numbers are very different.

Formatting each axis separately

Click on the left axis (the numbers on the left side) to select it, then right-click and choose Format Axis. You can change the minimum and maximum values, the number format, the font size, and the label text. For example, you might format the left axis to show currency (like $0, $10000, $20000) while the right axis shows plain numbers.

Click on the right axis to select it and format it the same way. You can also right-click the axis title (if it exists) to edit the text — change "Axis Title" to something like "Customer Count" or "Units Sold" so viewers understand what each axis measures. This labeling is important because without it, readers won't know which axis goes with which data series.

Choosing the right chart type for dual axes

Column and bar charts are the clearest choice for secondary axes because the bars sit side by side or one behind the other, making it obvious which series is which. Line charts also work well — one line can be solid and one dashed, or they can be different colors, so they don't overlap visually.

Area charts can work but may hide one series behind the other. Scatter plots and bubble charts support secondary axes but are less common for this purpose. Pie charts and doughnut charts do not support secondary axes at all. If you're unsure whether your chart type will work, create it and try moving a series to the secondary axis — Excel will either do it or tell you it can't.

Common problems and how to fix them

If your secondary axis appears but the data series didn't move, you may have selected the wrong series. Click directly on the bars, line, or data points themselves — not on the axis or the chart background. The selection squares should appear on the data points you want to move.

If the two series overlap and are hard to see, try changing the chart type or the order of the series. You can also adjust the gap width between columns (right-click the series, choose Format Data Series, and adjust the Gap Width slider) to make room for both. If gridlines are confusing, right-click them and delete them, or format them to be lighter or dashed.

Frequently Asked Questions

Can I add more than two axes to one chart?

Excel supports only one primary axis and one secondary axis per chart. If you need to plot three or more data series with different scales, you'll need to create separate charts or use a different visualization method like a dashboard with multiple small charts.

How do I change which axis is primary and which is secondary?

Right-click the series currently on the secondary axis and choose Format Data Series. In the Series Options tab, change "Plot Series On" back to Primary Axis. Then select the other series and move it to the secondary axis instead.

Why does my secondary axis show the same scale as the primary axis?

Excel sometimes auto-scales both axes to similar ranges. Right-click the secondary axis, choose Format Axis, and manually set the minimum and maximum values to match your data range. For example, if your secondary data ranges from 0 to 500, set the max to 500 instead of 50000.

Can I use a secondary axis with a pivot table chart?

Yes. Create the pivot table chart normally, then click the chart to select it and follow the same steps — right-click the data series you want to move and choose Format Data Series, then select Secondary Axis. The process is identical to a regular chart.

What's the difference between a secondary axis and a secondary chart?

A secondary axis is a second Y-axis on the same chart, which is what this article covers. A secondary chart is a separate, smaller chart embedded in the primary chart — it's a different feature found under the Insert menu and is less commonly used.