# LOGNORM.INV function

This article describes the formula syntax and usage of the LOGNORM.INV function (function: A prewritten formula that takes a value or values, performs an operation, and returns a value or values. Use functions to simplify and shorten formulas on a worksheet, especially those that perform lengthy or complex calculations.) in Microsoft Excel.

## Description

Returns the inverse of the lognormal cumulative distribution function of x, where ln(x) is normally distributed with parameters Mean and Standard_dev. If p = LOGNORM.DIST(x,...) then LOGNORM.INV(p,...) = x.

Use the lognormal distribution to analyze logarithmically transformed data.

## Syntax

`LOGNORM.INV(probability, mean, standard_dev)`

The LOGNORM.INV function syntax has the following arguments (argument: A value that provides information to an action, an event, a method, a property, a function, or a procedure.):

• Probability    Required. A probability associated with the lognormal distribution.
• Mean    Required. The mean of ln(x).
• Standard_dev    Required. The standard deviation of ln(x).

## Remarks

• If any argument is nonnumeric, LOGNORM.INV returns the #VALUE! error value.
• If probability <= 0 or probability >= 1, LOGNORM.INV returns the #NUM! error value.
• If standard_dev <= 0, LOGNORM.INV returns the #NUM! error value.

## Example

The example may be easier to understand if you copy it to a blank worksheet.

1. Select the example in this article. If you are copying the example in Excel Online, copy and paste one cell at a time.
Important: Do not select the row or column headers.

Selecting an example from Help

1. Press CTRL+C.
2. Create a blank workbook or worksheet.
3. In the worksheet, select cell A1, and press CTRL+V. If you are working in Excel Online, repeat copying and pasting for each cell in the example.
Important: For the example to work properly, you must paste it into cell A1 of the worksheet.
4. To switch between viewing the results and viewing the formulas that return the results, press CTRL+` (grave accent), or on the Formulas tab, in the Formula Auditing group, click the Show Formulas button.

After you copy the example to a blank worksheet, you can adapt it to suit your needs.

A B
Data Description
0.039084 Probability associated with the lognormal distribution
3.5 Mean of ln(x)
1.2 Standard deviation of ln(x)
Formula Description (Result)
=LOGNORM.INV(A2, A3, A4) Inverse of the lognormal cumulative distribution function for the terms above (4.000025)

Applies to:
Excel 2010, Excel Web App, SharePoint Online for enterprises, SharePoint Online for professionals and small businesses