FDIST Function

Excel Functions › Compatibility

All versions (legacy) Compatibility

The Excel FDIST function returns the right-tailed F probability distribution, used to compare the variability of two data sets. It is the legacy name of F.DIST.RT, introduced in Excel 2010.


Quick answer:
=FDIST(15,6,4) right-tail probability ≈ 0.0103

Syntax

=FDIST(x, deg_freedom1, deg_freedom2)
ArgumentDescription
xRequiredThe value at which to evaluate the function (must be ≥ 0).
deg_freedom1RequiredThe numerator degrees of freedom (a positive integer).
deg_freedom2RequiredThe denominator degrees of freedom (a positive integer).

How to use it

FDIST returns the right-tailed probability of the F distribution — the p-value for an F-test statistic with the given numerator and denominator degrees of freedom.

=FDIST(15,6,4) // right tail ≈ 0.0103
=FDIST(1,10,10) // equal variances = 0.5

Because it is right-tailed, the modern replacement is F.DIST.RT — not F.DIST, which is left-tailed. The inverse direction is provided by FINV / F.INV.RT.

Use F.DIST.RT instead: =F.DIST.RT(15,6,4) in Excel 2010+ returns the same right-tailed value. Note F.DIST (no .RT) is left-tailed and gives a different result.

Try it: interactive demo

Live demo

Pick a FDIST example to see the formula and its result.

Result:

Practice workbook

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Frequently asked questions

What is the modern replacement for FDIST?
F.DIST.RT, added in Excel 2010 — the right-tailed F distribution. =F.DIST.RT(15,6,4) equals =FDIST(15,6,4).
Is FDIST left-tailed or right-tailed?
Right-tailed — it returns the area to the right of x. That is why its modern equivalent is F.DIST.RT and not the left-tailed F.DIST.
What is the F distribution used for?
To compare the variances of two populations — the basis of the F-test and of ANOVA. The two degrees-of-freedom arguments come from the two samples.
What is the inverse of FDIST?
FINV (modern F.INV.RT): give it a right-tail probability and the two degrees of freedom and it returns the corresponding F value.

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Related functions: F.DIST.RT · FINV · FTEST · CHIDIST · EXPONDIST