CHIINV function

Returns the inverse of the one-tailed probability of the chi-squared distribution. If probability = CHIDIST(x,...), then CHIINV(probability,...) = x. Use this function to compare observed results with expected ones in order to decide whether your original hypothesis is valid.



Probability     is a probability associated with the chi-squared distribution.

Degrees_freedom     is the number of degrees of freedom.


  • If either argument is nonnumeric, CHIINV returns the #VALUE! error value.
  • If probability < 0 or probability > 1, CHIINV returns the #NUM! error value.
  • If degrees_freedom is not an integer, it is truncated.
  • If degrees_freedom < 1 or degrees_freedom > 10^10, CHIINV returns the #NUM! error value.

Given a value for probability, CHIINV seeks that value x such that CHIDIST(x, degrees_freedom) = probability. Thus, precision of CHIINV depends on precision of CHIDIST. CHIINV uses an iterative search technique. If the search has not converged after 100 iterations, the function returns the #N/A error value.


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

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Selecting an example from Help
  • Press CTRL+C.
  • In the worksheet, select cell A1, and press CTRL+V.
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Data Description
0.050001 Probability associated with the chi-squared distribution
10 Degrees of freedom
Formula Description (Result)
=CHIINV(A2,A3) Inverse of the one-tailed probability of the chi-squared distribution (18.3069735)
Applies to:
Excel 2007