Often you may want to add custom error bars to a bar graph in Google Sheets.

Fortunately this is easy to do and the following step-by-step example shows how to add the following custom error bars to a graph in Google Sheets:

Let’s jump in!

**Step 1: Enter the Data**

First, let’s enter the following dataset that shows the mean plant growth, standard deviation of plant growth and sample size of three different fertilizers that were applied to a field:

**Step 2: Calculate the Half-Width of the Confidence Intervals**

Next, we will calculate the half width of a confidence interval for a mean for each group, which we will later use for the length of the error bars in the graph.

To do so, type the following formula into cell **E2**:

=CONFIDENCE.T(0.05, C2, D2)

Then click and drag this formula down to the remaining cells in column E to calculate the half width of the confidence interval for each group:

**Note**: We chose to use an alpha value of **.05** to calculate the half width for a 95% confidence interval.

You can find the complete documentation for the **CONFIDENCE.T** function in Google Sheets here.

**Step 3: Create Bar Chart with Custom Error Bars**

Next, highlight the cell range **B2:B4**, then click the **Insert** tab along the top ribbon, then click **Chart**.

In the **Chart editor** panel that appears on the right side of the screen, click the **Setup **tab, then check the box next to **Switch rows / columns**:

At this point, the bar chart should look like this:

The height of the bars represent the mean plant growth for each fertilizer.

Next, click the **Customize** tab in the **Chart editor**, then click the dropdown arrow next to **Series**, then choose **Column1**:

Then check the box next to **Error bars**, then click **Constant** under the **Type** dropdown menu, then type in **1.404**, which represents the half width of the confidence interval that we calculated earlier for Fertilizer A:

Repeat this process for Fertilizer B and Fertilizer C.

The end result will be that each bar in the graph has its own custom error bar length that represents the 95% confidence interval for the mean:

**Additional Resources**

The following tutorials explain how to perform other common tasks in Google Sheets:

Google Sheets: How to Sort Bars in Bart Chart

Google Sheets: How to Create a Clustered Stacked Bar Chart

Google Sheets: How to Create a Stacked Bar Chart