Author: Oscar Cronquist Article last updated on October 23, 2018

The GAMMADIST function calculates the gamma often used in queuing analysis in probability statistics.

This function is outdated and has been replaced by the GAMMA.DIST function which was introduced in Excel 2010.

Formula in cell C7:


Excel Function Syntax



x Required.
alpha Required.
beta Required. 1 returns the standard gamma distribution.
cumulative Required. A boolean value.
TRUE - cumulative distribution function
FALSE - probability density function


The GAMMADIST function returns

  • #VALUE! error value if alpha, beta or x is non-numeric.
  • #NUM! error value if:
    • x < 0 (zero)
    • alpha <= 0 (zero)
    • beta <= 0 (zero)

The equation to calculate the gamma probabiltiy density function:

The standard gamma probability function: