How to prepare a linear graph in Excel

1. Enter your data in two columns. The first column should include the x variable, and the second should have the y-variable. In this case I am comparing absorbance data to the concentration of X:

2. Select both columns by clicking and dragging across the column headers (labeled “A” and “B” in the above example.

3. Click on the chart wizard on the Excel tool bar.

4. Select scatter plot from the menu that appears to the left of the Chart Wizard window, and then select the plot subtype that shows only data points, but no line. Then click on “Next>”.

5. The next window that appears will give you a preview of your plot. Hopefully, it’s what you were expecting. If so, just press “Next>”.

6. Now you can have some fun using each of the tabs in the “Step 3” window of the Chart Wizard:

Titles: Use this section to label the x- and y-axis (don’t forget units).

Axes: I usually don’t touch this.

Gridlines: I hate ‘em. Turn ‘em off by unchecking their boxes.

Legend: I usually turn the legend off too. Uncheck the “show legend” button.

Data Labels: Never touch ‘em.

7. Click “Finish” and you should now have a graph on your worksheet that looks like this:

You can monkey with the axes and the borders by double clicking hither and yon on the graph. If you screw up, select “Clear All” from the “Edit” menu and try again.

8. Select the graph by clicking on it. It should look like the plot above, with black squares framing the plot. Under the “Chart” menu, select “Add Trendline”.

9. Click on “Linear” so that it is highlighted as above. Then click on the “Options” tab, and indicate (if appropriate) that you want an intercept of zero and that you want to see the equation.

Typically you don’t keep the equation on figures in you plot, but it is what you’re after. Click on “OK”.

10. If all has gone well, you’ve finished your work!