How to Use Error Bars in Excel

Excel 2007
1. Click the chart you want you want to add an error bar to.
2. Click the 'Chart Tools > Layout' tab.
3. Click 'Error Bars' in the Analysis section of the Layout tab.
4. Click the type of error bars you want to add. You may choose error bars with Standard Error, Percentages, or Standard Deviation.
5. Select the display type for the error bars in the Format Error Bars dialog.
6. Set the error amount in the appropriate text box.
7. Click 'OK' to exit the Format Error Bars dialog.
Excel 2003
8. Double click the chart series you want to add an error bar to.
9. Choose the 'Y Error Bars' or 'X Error Bars' rab in the Format Data Series dialog, depending on which axis you want to add the bars to.
10. Choose the 'Display' type you want by clicking the appropriate icon, and set the Error Amount values in the appropriate text box.
11. Click 'OK' to the close the Format Data Series dialog.