How to add a secondary axis to a chart

In this video, we'll look at how to add a secondary axis to chart.

Here we have some website data that includes orders and the conversion rates for five different channels.

Let me first insert a column chart to plot orders per channel.

Now, let's say I'd like to also add the conversion rate into this chart.

I can easily do that by selecting the chart and dragging the data area to include conversion.

But now we see a problem. The conversion rate is measured as a percentage, where all numbers are less than 1, while the orders are much bigger numbers.

As a result, the conversion rate columns are too short to see. The solution is to plot this data on a secondary vertical axis, configured for percentages.

Now, I want to point out that you can add a secondary axis with the format task pane, though it's not ideal, for reasons I'll explain.

To do this, start by selecting the conversion series.

Its hard to select because it's so small, so you can right-click the chart and use the mini toolbar. Then visit Series Options in the Format Task pane.

Now if the Format Task pane isn't open, select the conversion series, then use control 1 to open the Format Task pane.

Now you can change the series to the secondary axis. This works, but you can see 
the conversion columns sit directly on top of the orders.

For a chart like this, you'll probably want to use a line instead.

So, right-click the chart and choose change chart type. By adding the secondary axis, the chart has already changed into a combo chart. So I just need to change conversion to a line.

So, as you're watching this, you might guess that changing the chart type is a better way to do this from the start. And you'd be right. Let's try that out.

First, I'll undo back to the point where I first added the conversion data series.

Then I'll right-click, select change chart type, and select combo. Excel already suggests a line, so the only thing I need to do is tick the secondary axis box.

You can see this is a much simpler way to add a secondary axis.

Finally, notice the secondary axis is an ordinary value axis. The axis options area in the Format Task pane includes all standard value axis settings.