The Excel F.DIST Function

Related Functions:
F.DIST.RT
F.INV

Basic Description

The Excel F.DIST function calculates the Probability Density Function or the Cumulative Distribution Function for the F Distribution. This function is frequently used used to measure the degree of diversity between two data sets.

The function is new to Excel 2010 and so is not available in earlier versions of Excel.

The syntax of the F.Dist function is:

F.DIST( x, deg_freedom1, deg_freedom2, cumulative )

Where the function arguments are:

x-The (positive) numeric value at which the function is to be evaluated.
deg_freedom1-An integer specifying the numerator degrees of freedom.
deg_freedom2-An integer specifying the denominator degrees of freedom.
cumulative-

A logical argument that specifies the type of F Distribution to be calculated. This can be either:

TRUE-use the cumulative distribution function
FALSE-use the probability density function

If either deg_freedom1 or deg_freedom2 are decimal numbers, these are truncated to integers by Excel.


F.Dist Function Examples

Example 1 - Probability Density Function

Plot of the Probability Density F Distribution with numerator degrees of freedom = 2 and denominator degrees of freedom = 5
F Prob. Distribution with deg_freedom1 = 2 & deg_freedom2 = 5

The above chart on the right shows the probability density function for the F Distribution with the numerator degrees of freedom equal to 2 and the denominator degrees of freedom equal to 5.

If you want to use Excel to calculate the value of this function at x = 1, this can be done using the F.Dist function, as follows:

=F.DIST( 1, 2, 5, FALSE )

This gives the result 0.308000822.



Example 2 - Cumulative Distribution Function

Plot of the Cumulative F Distribution with numerator degrees of freedom = 2 and denominator degrees of freedom = 5
Cumulative F Distrib. with deg_freedom1 = 2 & deg_freedom2 = 5

The above chart on the right shows the Cumulative F Distribution function with the numerator degrees of freedom equal to 2 and the denominator degrees of freedom equal to 5.

If you want to use Excel to calculate the value of this function at x = 1, this can be done using the F.Dist function, as follows:

=F.DIST( 1, 2, 5, TRUE )

This gives the result 0.56879885.


Further details and examples of the Excel F.Dist function are provided on the Microsoft Office website.


F.Dist Function Errors

If you get an error from the Excel F.Dist function this is likely to be one of the following:

Common Errors
#NUM!-

Occurs if either:

  • The supplied value of x is < 0
or
  • The supplied deg_freedom1 or deg_freedom2 is < 1.
#VALUE!-Occurs if any of the supplied arguments are non-numeric.