When the values in a chart vary widely from data series to data series, you can plot one or more data series on a secondary axis. A secondary axis can also be used as part of a combination chart when you have mixed types of data (for example, price and volume) in the same chart.

On a chart, click the horizontal (category) axis that you want to change, or do the following to select the axis from a list of chart elements: Click anywhere in the chart. This displays the Chart Tools, adding the Design, Layout, and Format tabs.

When a chart displays a secondary vertical (value) axis, you can also change the scale of that axis. For more information about displaying a secondary vertical axis, see Add or remove a secondary axis in a chart.

Change the chart type of one or more data series in your chart (graph) and add a secondary vertical (value) axis in the combo chart. Create a combo chart with a secondary axis. In Excel 2013, you can quickly show a chart, like the one above, by changing your chart to a combo chart.

The horizontal (category) axis, also known as the x axis, of a chart displays text labels instead of numeric intervals and provides fewer scaling options than are available for a vertical (value) axis, also known as the y axis, of the chart.

Add a data series to your chart. Add or remove a secondary axis in a chart in Excel. Change the data series in a chart

You can add a title to each axis in a chart. Axis titles are typically available for all axes that can be displayed in a chart, including depth (series) axes in 3-D charts. Some chart types (such as radar charts) have axes, but they cannot display axis titles.

When you create a chart from worksheet data that uses dates, and the dates are plotted along the horizontal (category) axis in the chart, Excel automatically changes the category axis to a date (time-scale) axis. You can also manually change a category axis to a date axis.

For example, if your chart is a 3-D chart, you will see Depth gridline options, and if your chart has a secondary horizontal axis, you will see Secondary horizontal and vertical gridline options.

Change the text and format of category axis labels and the number format of value axis labels in your chart (graph).