F.INV Function

Excel Functions › Statistical

Excel 2010+ Statistical

The Excel F.INV function returns the inverse of the left-tailed F distribution — given a probability, it returns the F value at which the cumulative area to the left equals that probability.


Quick answer:
=F.INV(0.99,6,4) critical F value ≈ 15.21

Syntax

=F.INV(probability, deg_freedom1, deg_freedom2)
ArgumentDescription
probabilityRequiredA probability associated with the F distribution, between 0 and 1.
deg_freedom1RequiredThe numerator degrees of freedom (a positive integer).
deg_freedom2RequiredThe denominator degrees of freedom (a positive integer).

How to use it

F.INV is the inverse of F.DIST: you supply a left-tail probability and it returns the matching F value. It answers “what F statistic has this much area to its left?”

=F.INV(0.99,6,4) // ≈ 15.21
=F.DIST(15.21,6,4,TRUE) // ≈ 0.99 (round trip)

Because it works from the left tail, F.INV(0.99, d1, d2) finds the upper critical value — the same point you would get from F.INV.RT(0.01, d1, d2). The two are equivalent: a 0.99 left-tail probability is a 0.01 right-tail probability.

Use F.INV to find critical cutoffs when running an F-test by hand: choose your significance level, convert it to the appropriate tail probability, and read off the critical F.

Tip: For an upper-tail critical value at the 5% level, F.INV(0.95, d1, d2) and F.INV.RT(0.05, d1, d2) give the same number — pick whichever reads more naturally in your sheet.

Try it: interactive demo

Live demo

Enter a left-tail probability and the two degrees of freedom to build the inverse formula.

Critical F value computed live in Excel; this demo echoes the formula.

Practice workbook

📊
Download the free F.INV practice workbook
Every example on this page, ready to open in Excel — plus practice challenges with answers on a separate tab. No sign-up required.

Frequently asked questions

What does F.INV return?
The inverse of the left-tailed F distribution: given a probability between 0 and 1, it returns the F value whose cumulative area to the left equals that probability. It is the reverse of F.DIST(...,TRUE).
What is the difference between F.INV and F.INV.RT?
F.INV takes a left-tail probability; F.INV.RT takes a right-tail probability. They are linked by F.INV(p,d1,d2) = F.INV.RT(1−p,d1,d2), so they return the same value for complementary probabilities.
Why do F.INV(0.99,...) and F.INV.RT(0.01,...) give the same answer?
A 0.99 probability to the left is the same point as a 0.01 probability to the right, since the two tails sum to 1. Both return the upper critical F value (about 15.21 for 6 and 4 degrees of freedom).
How is F.INV different from the legacy FINV?
The old FINV takes a right-tail probability, matching today's F.INV.RT. F.INV (2010+) is the new left-tailed inverse function.

Master functions like this in one day

This page covers one function. Our Excel Formulas and Functions class covers the 30 that matter most — live, hands-on, taught by professionals in Dallas–Fort Worth, Houston, Austin, Oklahoma City, Denver, or online.

See the Formulas & Functions Class

Related functions: F.INV.RT · F.DIST · F.DIST.RT · F.TEST · CHISQ.INV · T.INV