You can use the **LINEST** function in Excel to find the uncertainty of the slope of a regression line.

The following example shows exactly how to do so.

**Example: How to Find Uncertainty of Slope in Excel**

Suppose we have the following dataset in Excel:

Suppose we would like to fit a linear regression model to this dataset and find the uncertainty of the slope of the regression line.

We can use the **LINEST** function to do so, which uses the following basic syntax:

LINEST(known_y's, known_x's, const, stats)

where:

**known_y’s**: A column of values for the response variable**known_x’s**: One or more columns of values for the predictor variables**const**: TRUE = calculate intercept normally, FALSE = force intercept to be zero**stats**: TRUE = calculate additional regression statistics, FALSE = only calculate coefficients

We can type the following formula into cell **D1** to fit a simple linear regression model to this dataset:

=LINEST(B2:B15, A2:A15, TRUE, TRUE)

The output from the **LINEST** function contains the coefficients of the regression model along with several additional statistics:

The following screenshot provides an explanation of each value in the output:

From the output we can see:

- The value for the slope is
**0.693717**. - The value for the uncertainty of the slope is
**0.070978**.

All of the other values in the output from the **LINEST** function provide us with additional information about the overall fit of the regression model.

**Additional Resources**

The following tutorials explain how to perform other common operations in Excel:

Excel: How to Interpret Output of LINEST Function

Excel: How to Use LINEST to Perform Multiple Linear Regression

Excel: How to Add a Regression Line to a Scatterplot