On some charts, you may want to plot a data series that contains different numbers on a different scale. For example, you may want to show monthly sales figures and percentages on the same chart. If you use the same scale for both data series, the percentages will be too small to show up on the chart.
To plot a data series on a secondary axis:
- Create your chart.
- Select the smaller data series by clicking the drop-down list on the Layout tab of the Chart Tools ribbon.
- Click the Format Selection button.
- Excel will display the Format Data Series dialog box
- In the Series Options category, select Secondary Axis.
- Click the Close button.
- Excel will plot the data series on a secondary axis.