# Excel Intercept Function

Intercept Equation

The Excel Intercept Function uses the following equation to calculate the intercept of the linear regression line through a set of given points:

where the slope, b is given by the equation:

and the values of   x   and   y   are the sample means (the averages) of the known x- and y-values.

Related Function:
SLOPE

## Function Description

The Excel Intercept function calculates the intercept (the value at the intersection of the y axis) of the linear regression line through a supplied set of x- and y- values.

The syntax of the function is:

INTERCEPT( known_y's, known_x's )

Where the arguments are:

 known_y's - The array known y-values. known_x's - The array of known x-values.Note that the length of the known_x's array should be the same length as known_y's, and the variance of the known_x's must not be zero.

## Intercept Function Example

The spreadsheet below shows an example of the Excel Intercept function used to calculate the point at which the linear regression line through the known_x's and known_y's (listed in cells F2:F7 and G2:G7) intersects the y-axis.

The known_x's and known_y's are plotted on the chart in the spreadsheet.

As shown in cell F9 of the spreadsheet, the formula for the Intercept function is:

=INTERCEPT( G2:G7, F2:F7 )

which gives the result 2.4.

For further examples of the Excel Intercept function, see the Microsoft Office website

## Intercept Function Errors

If you get an error from the Excel Intercept function, this is likely to be one of the following:

Common Errors
 #N/A - Occurs if the supplied known_x's and known_y's arrays are of different lengths. #DIV/0! - Occurs if either:The variance of the supplied known_x's is equal to zeroorEither of the supplied known_x's or known_y's arrays is empty.