The Excel GAMMA Function

Related Functions:
GAMMA.DIST
GAMMALN.PRECISE
Gamma Function

The Gamma Function, Γ(n), is calculated by the following formula:

Gamma Function Equation
The function is explained in detail on the Wikipedia Gamma Function page.

Basic Description

The Excel GAMMA function returns the value of the Gamma Function, Γ(n), for a specified number, n.

Note: The Gamma function is new in Excel 2013 and so is not available in earlier versions of Excel.

The syntax of the function is:

GAMMA( number )

where the number argument is a positive real number.


Gamma Function Examples

Gamma Function Chart
Gamma Function Γ(n) for 0.0083 ≤ n ≤ 6

The above chart on the right shows the Gamma Function, Γ(n), for 0.0083 ≤ n ≤ 6.

In the spreadsheets below, the Excel Gamma function is used to evaluate this function for four different values of n.

 Formulas:
 A
1=GAMMA( 0.1 )
2=GAMMA( 1 )
3=GAMMA( 1.5 )
4=GAMMA( 5.5 )
 Results:
 A
19.513507699
21
30.886226925
452.34277778

Further examples of the Excel Gamma function are provided on the Microsoft Office website.


Gamma Function Errors

If you get an error from the Excel Gamma Function, this is likely to be one of the following:

Common Errors
#NUM!-Occurs if the supplied number argument is ≤ 0.
#VALUE!-Occurs if the supplied number argument is non-numeric.