The Excel CHISQ.INV.RT Function

Related Functions:

The Chisq.Inv.Rt function is the inverse of the Excel Chisq.Dist.Rt function.

I.e., for a supplied probability, the Chisq.Inv.Rt function finds the value of x such that:

Chisq.Dist.Rt( x, degrees_freedom ) = probability

Basic Description

The Excel Chisq.Inv.Rt function calculates the inverse of the right-tailed probability of the Chi-Square Distribution.

The function is new in Excel 2010 and so is not available in earlier versions of Excel. However, the Chisq.Inv.Rt function is simply an updated version of the Chiinv function that is available in earlier versions of Excel.

The syntax of the Chisq.Inv.Rt function is:

CHISQ.INV.RT( probability, degrees_freedom )

Where the function arguments are:

probability-The probability of the right-tailed chi-square distribution, for which you want to find the value of x.

The number of degrees of freedom (must be a positive integer).

(If the supplied degrees_freedom is a decimal, this is truncated to an integer).

Chisq.Inv.Rt Function Examples

The spreadsheets below show examples of the Excel Chisq.Inv.Rt function, used to calculate the inverse of the right-tailed chi-square distribution for different probability values, and different degrees of freedom.

The spreadsheet on the left shows the formulas and the spreadsheet on the right shows the results.

1=CHISQ.INV.RT( 0.5, 1 )
2=CHISQ.INV.RT( 0.75, 1 )
3=CHISQ.INV.RT( 0.1, 2 )
4=CHISQ.INV.RT( 0.8, 2 )
5=CHISQ.INV.RT( 0.25, 3 )

Further examples of the Excel Chisq.Inv.Rt function can be found on the Microsoft Office website.

Chisq.Inv.Rt Function Errors

If you get an error from the Excel Chisq.Inv.Rt function this is likely to be one of the following:

Common Errors

Occurs if either:

  • the supplied probability value is ≤ 0 or > 1;
  • the supplied degrees_freedom argument is <1.
#VALUE!-Occurs if any of the supplied arguments are not recognised as numeric values.