Author: Oscar Cronquist Article last updated on September 28, 2018

The CHISQ.INV.RT function was introduced in Excel 2010 and calculates the inverse of the right-tailed probability of the chi-squared distribution. It has replaced the CHIINV function.

Formula in cell C6:


Excel Function Syntax



probability Required. A numerical value representing the probability of the chi-squared function distribution.
deg_freedom Required. A numerical value representing the degrees of freedom.


The CHISQ.INV.RT function returns

  • #VALUE! error value
    • if probability or deg_freedom argument is non-numeric.
    • if the iterative search can't find a solution after 64 iterations.
  • #NUM! error value if:
    • probability < 0 (zero)
    • probability > 1 (zero)
    • deg_freedom  < 1

deg_freedom argument is converted into integers if necessary. CHISQ.DIST.RT and CHISQ.INV.RT are related:

  •  CHISQ.DIST.RT(x, deg_freedom) = probability
  • CHISQ.INV.RT(probability,deg_freedom) = x