How to Add a Second Y Axis to a Graph in Microsoft Excel

Part 1 of 2:

Create a spreadsheet with your data. Each data point should be contained in an individual cell with rows and columns that are labeled.
Select the data you want to graph. Click and drag to highlight all the data you want to graph. Be sure to include all data points and the labels.
1. If you don't want to graph the entire spreadsheet, you can select multiple cells by holding Ctrl and clicking the cells you want to graph.
Click Insert. It's in the menu bar at the top of the page. This displays the Insert panel at the top.
Click the icon that resembles a chart type you want to create. This generates a chart based on the selected data.
1. You can also add a second axis to a line graph or a bar graph.
Double-click the line you want to graph on a second axis. Clicking the line once highlights each individual data point on the line. Double-clicking it displays the "Format Data Point" menu to the right.^{[1] X Research source}
Click the icon that resembles a bar chart. This is the "Series Options" icon. It's at the top of the Format Data Point menu to the right.
Select the radio button for "Secondary Axis". It's below "Series Options" in the Format Data Point menu. This immediately displays the line on a secondary axis with the numbers on the right side.

Part 2 of 2:

Right-click the chart. The chart is in the middle of the Excel spreadsheet. This displays a menu next to the line in the chart.
Click Change Series Chart Type. This displays a window that allows you to edit the chart.
Click the checkbox next to any other lines you want to add to the Y-axis. To add other lines to the Y-axis, click the checkbox below "Y-axis" to the right of the data series in the lower-right corner of the window.
Select the type of chart for each data series. In addition to graphing a data series on a separate Y-axis, you can also graph it on a different chart type. Use the drop-down menu to select the chart type for each data series in the lower-right corner of the window.
Click Ok. This saves the changes you made to the chart.
1. If you want to change the chart type for the entire chart, click the chart type in the menu to the left of the window and then double-click the chart style in the window.