Gammaln function

This article describes the formula syntax and usage of the GAMMALN function in Microsoft Excel.

Description

Returns the natural logarithm of the gamma function, Γ(x).

Syntax

GAMMALN(x)

The GAMMALN function syntax has the following arguments:

• X    Required. The value for which you want to calculate GAMMALN.

Remarks

• If x is nonnumeric, GAMMALN returns the #VALUE! error value.

• If x ≤ 0, GAMMALN returns the #NUM! error value.

• The number e raised to the GAMMALN(i) power, where i is an integer, returns the same result as (i - 1)!.

• GAMMALN is calculated as follows:

  

  where:

  

Example

Copy the example data in the following table, and paste it in cell A1 of a new Excel worksheet. For formulas to show results, select them, press F2, and then press Enter. If you need to, you can adjust the column widths to see all the data.

Formula	Description	Result
=GAMMALN(4)	Natural logarithm of the gamma function at 4.	1.7917595