LOGNORMDIST Function

All versions (legacy) Compatibility

The Excel LOGNORMDIST function returns the cumulative lognormal distribution — the probability that a positive, right-skewed variable falls at or below x. It is a legacy function; Microsoft replaced it in Excel 2010 with LOGNORM.DIST, which adds a cumulative option.

Quick answer:

=LOGNORMDIST(4,3.5,1.2) cumulative probability ≈ 0.039

Syntax

=LOGNORMDIST(x, mean, standard_dev)

Argument		Description
`x`	Required	The value at which to evaluate the distribution (must be > 0).
`mean`	Required	The mean of ln(x) — the mean of the underlying normal distribution.
`standard_dev`	Required	The standard deviation of ln(x) (must be > 0).

How to use it

LOGNORMDIST gives the cumulative probability for a lognormal variable — one whose natural log is normally distributed. The legacy function is cumulative only: it always returns P(X ≤ x), with no flag to request the density.

=LOGNORMDIST(4,3.5,1.2) // CDF ≈ 0.039

=LOGNORMDIST(33.12,3.5,1.2) // at the median ≈ 0.5

The inverse, LOGINV (modern LOGNORM.INV), turns a probability back into x. Remember that mean and standard_dev describe ln(x), not x.

Use LOGNORM.DIST in Excel 2010 and later. The modern LOGNORM.DIST adds a fourth cumulative argument so you can return the density (PDF) as well as the cumulative probability. LOGNORMDIST is kept only for backward compatibility.

Try it: interactive demo

Live demo

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

example

Result:

Practice workbook

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Frequently asked questions

Should I use LOGNORMDIST or LOGNORM.DIST?

Use LOGNORM.DIST in Excel 2010 or later. It takes the same x, mean, standard_dev plus a cumulative flag; LOGNORMDIST is retained only for older workbooks.

Why does LOGNORMDIST have no cumulative argument?

The legacy function only returns the cumulative probability P(X ≤ x). To get the probability density instead, use LOGNORM.DIST with its fourth argument set to FALSE.

What do the mean and standard_dev arguments describe?

They describe ln(x), the underlying normal distribution — not the lognormal variable directly. mean is the mean of ln(x) and standard_dev is its standard deviation.

How does LOGNORMDIST relate to LOGINV?

They are inverses. LOGNORMDIST maps an x to a cumulative probability; LOGINV maps a probability back to x using the same mean and standard deviation.

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Related functions: LOGNORM.DIST · LOGINV · NORMDIST · NORMSDIST · EXP