Using Excel 2010 - Add Error Bars to a Graph

The estimated error on each point in the graph should be displayed as "error bars". Any line which fits all the experimental points within their estimated error ranges is in agreement with experiment. Small residual misfits (i.e. the line only just fails to fit the experimental points and their errors) may well be due to underestimation of the limits of error of individual readings.

The following procedure (using the graph generated in the Plotting Graphs section of this tutorial) details how these can be added:

 1.Click on the Layout tab under Chart Tools.
 2.Click on Error Bars, followed by More Error Bars Options...
 3.Click on the circle to the left of Custom, then click Specify Value.
 4.Type 0.03 (the estimated error on the absorbance measurements in this example) in both boxes.
 5.Click on OK, then Close
 6.Your graph should now look like that shown opposite.

Note that an "uninformative" graph title has been used.

A Note on Displaying X-Error Bars

To add x-error bars to your plot:

Note: If y-error bars have appeared but are not needed: Click on one of the y-error bars on your plot and press Delete.

Add Non-Linear Error Bars to a Graph

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