Primarily used in analytical chemistry, a calibration curve, sometimes called a standard or reliability curve, is used to compare samples of known and unknown concentrations.

You may use it to measure an instrument comparing estimated parameters against a set of actual values or standards. You can then determine the reliability of uncertainty.

Table of Contents

    If you want to create a calibration curve, you can do so in Microsoft Excel in just minutes. As long as you have the dataset for the graph, you’re ready to go.

    How to Create a Calibration Graph/Curve in Microsoft Excel image 1

    How to Create a Calibration Graph in Excel

    To create your calibration curve in Excel, you’ll need your sets of data for the x- and y-axis. You can then add a trendline for a linear calibration curve and display the equation before customizing the graph.

    Create the Graph

    Select the calibration data for the chart. The data in the first column is for the x-axis (horizontal) and the second column is for the y-axis (vertical).

    1. If you have adjacent cells, simply drag your cursor through them. Otherwise, select the first set, hold Ctrl on Windows or Command on Mac, and select the second set.
    How to Create a Calibration Graph/Curve in Microsoft Excel image 2
    1. Go to the Insert tab and open the Insert Scatter or Bubble Chart drop-down menu in the Charts section. Choose Scatter.
    How to Create a Calibration Graph/Curve in Microsoft Excel image 3

    You’ll then see the scatter plot with your data.

    How to Create a Calibration Graph/Curve in Microsoft Excel image 4

    Add the Trendline

    To add the trendline, do one of the following:

    • On the Chart Design tab, select Add Chart Element, move to Trendline, and pick Linear.
    • Right-click a data point, select Add Trendline, and pick Linear in the sidebar that displays.
    • On Windows, select the Chart Elements button, check the box for Trendline, and pick Linear in the pop-out menu.
    How to Create a Calibration Graph/Curve in Microsoft Excel image 5

    Note that although a Linear trendline is common for a calibration curve, you can choose a different type if needed.

    Display the Equation

    1. To add the equation and R-squared value to the chart, right-click the Trendline and choose Format Trendline.
    How to Create a Calibration Graph/Curve in Microsoft Excel image 6
    1. When the Format Trendline sidebar opens, make sure you’re on the Trendline Options tab. Then, check the two boxes at the bottom for Display Equation on chart and Display R-squared value on chart.
    How to Create a Calibration Graph/Curve in Microsoft Excel image 7
    1. You can use the X to close the sidebar and see both values displayed on the top right of the trendline.
    How to Create a Calibration Graph/Curve in Microsoft Excel image 8

    As you can see, our R-squared value is 0.9888 which is close to 1.0 and means that our calibration curve is reliable.

    How to Create a Calibration Graph/Curve in Microsoft Excel image 9

    Customize the Calibration Graph in Excel

    Like other types of charts you create in Excel, you can customize your calibration graph too. You can change the default title, add axis titles, adjust the color scheme, resize your chart, and customize other options per your preference.

    Change the Chart Title

    By default, the title of your calibration graph is “Chart Title.” Simply select the text box containing this title and enter your own.

    How to Create a Calibration Graph/Curve in Microsoft Excel image 10

    If you don’t see the chart title, go to the Chart Design tab, open Add Chart Elements, move to Chart Title, and choose a location.

    How to Create a Calibration Graph/Curve in Microsoft Excel image 11

    Add Axis Titles

    You can add titles to the vertical, horizontal, or both axes. On the Chart Design tab, open the Add Chart Element menu, move to Axis Titles, and choose one or both options.

    How to Create a Calibration Graph/Curve in Microsoft Excel image 12

    On Windows, you can also select the Chart Elements button, check the box for Axis Titles, and mark the boxes for those you want to use.

    How to Create a Calibration Graph/Curve in Microsoft Excel image 13

    Once you see the Axis Title, select the text box with the title and enter your own.

    How to Create a Calibration Graph/Curve in Microsoft Excel image 14

    Adjust the Color Scheme

    Depending on the purpose of your calibration graph, you may want to use complementary colors.

    Select the graph, go to the Chart Design tab, and choose a color scheme in the Change Colors drop-down menu. You can also use the Chart Styles box to the right for a different design.

    How to Create a Calibration Graph/Curve in Microsoft Excel image 15

    On Windows, you can select the Chart Styles button and use the Colors tab to choose your color scheme.

    How to Create a Calibration Graph/Curve in Microsoft Excel image 16

    Resize the Graph

    You can make the calibration graph larger or smaller by simply dragging in Excel. Select the chart and then drag a corner or edge, releasing when you have the size you want.

    How to Create a Calibration Graph/Curve in Microsoft Excel image 17

    For other customization options, review the tools on the Chart Design tab or right-click the graph, choose Format Chart, and use the options in the Format Chart Area sidebar.

    How to Create a Calibration Graph/Curve in Microsoft Excel image 18

    Using your calibration data and a scatter chart, you can pop a calibration curve into your Excel spreadsheet with little effort. Then, use the chart tools to make its appearance more appealing.

    For more, look at how to make a bell curve chart in Excel.