Statistical

GAMMA.INV Function in Excel

Returns the inverse of the gamma cumulative distribution.

Syntax

  • =GAMMA.INV(probability, alpha, beta)

Arguments

  • probability (required): Probability (0 to 1)
  • alpha (required): Shape parameter
  • beta (required): Scale parameter

Examples

  • =GAMMA.INV(0.323, 3, 2) - Inverse gamma - Result: 2

GAMMA.INV for data analysis

  • Confirm whether you need entire columns, filtered subsets, or distinct values.
  • Use [COUNTIFS](/functions/countifs/) and [SUMIFS](/functions/sumifs/) for multi-criteria metrics.
  • Pivot tables complement single-cell statistical formulas for exploration.

Common errors

  • #NUM! if probability not between 0 and 1

Use cases

  • Statistical modeling
  • Simulation
  • Risk analysis

Frequently asked questions

  • What is the GAMMA.DIST function in Excel? GAMMA.DIST returns the gamma probability distribution, used for modeling waiting times, reliability analysis, and situations where you're modeling the time until the nth event occurs.
  • When should I use GAMMA.DIST in real applications? Use GAMMA.DIST for reliability engineering (time to failure), queuing theory (service times), project management (task duration modeling), and financial risk analysis.
  • What parameters does GAMMA.DIST require? GAMMA.DIST needs: x (value to evaluate), alpha (shape parameter), beta (scale parameter), and cumulative (TRUE for cumulative distribution, FALSE for probability density).
  • How do I choose alpha and beta parameters? Alpha controls the shape (higher values make it more bell-shaped), beta controls the scale (higher values stretch the distribution). Estimate from data using method of moments or maximum likelihood.

Editorial review

  • Reviewed by Excel.Directory Editorial Team. Updated May 2026.