How to Make a Calibration Curve Graph in Excel 2007

By Stephanie Ellen

A calibration curve is used in analytical chemistry to figure out the concentration of a substance in a sample, by comparing the sample to a set of predetermined data. In order to build a calibration curve in Excel 2007, you should already have your experimental data formatted in a worksheet with columns (x, y) and column headers. For example, if you want to plot absorbance vs. concentration, put your absorbance values in column A and your concentration values in column B.

Things You'll Need

  • Worksheet with experimental data

Step 1

Highlight both columns of your data. Left-click on the top left of your data, then drag the mouse to the bottom-right of your data.

Step 2

Click the "Insert" ribbon.

Step 3

Click the "Scatter" button in the Charts section of the Insert ribbon. Click the bottom-right icon in the Scatter Plot drop-down list. The icon has squares with lines between them. The ribbon has now automatically switched to “Design,” and your plot has appeared on screen.

Step 4

Click “Select Data,” in the Data section of the Design ribbon.

Step 5

Click the list item titled “Series1,” then click "Edit" right above that.

Step 6

Type “Calibration Curve” in the “Series Name” text box. Press "OK."

Step 7

Press "OK" again, and you are back on your spreadsheet with the Calibration Curve plot.

Tips & Warnings

  • “Absorbance” should be the first data column, and “Concentration” should be the second column. If they are reversed, your plot axes will also be reversed.
  • The calibration curve is never exact: it only gives you an estimate of the concentration. Make sure you build in an allowance for error into your calculations.