How to Plot a Secondary Axis on Microsoft Excel

Secondary Vertical Axis
1. Open the spreadsheet in Excel that contains the chart to which you want to add a secondary axis. Click the 'Microsoft Office' button, then click 'Open' and then locate the file on your computer. Click 'Open' to open the file. Your existing chart should pop up on the screen when you open the spreadsheet. Depending on the type of graph you created, it could be a bar chart, line graph or other graph type.
2. Click the data series in the chart you want to plot on a secondary axis.
3. Click the 'Format' tab, then click 'Format Selection' in the 'Current Selection' group.
4. Click the 'Series Options' tab, then click 'Secondary Axis' below 'Plot Series On.' The secondary axis will be display in the chart.
Secondary Horizontal Axis
5. Click anywhere on the chart to display Chart Tools.
6. Click the 'Layout' tab, then click on 'Axes' from the 'Axes' group.
7. Click 'Secondary Horizontal Axis,' then click the type of display you want. For example, if you want an unlabeled axis, click 'Show Axis Without Labeling.'