This article describes the formula syntax and usage of the CHISQ.INV function in Microsoft Excel.
Returns the inverse of the lefttailed probability of the chisquared distribution.
The chisquared distribution is commonly used to study variation in the percentage of something across samples, such as the fraction of the day people spend watching television.
Syntax
CHISQ.INV(probability,deg_freedom)
The CHISQ.INV function syntax has the following arguments:

Probability Required. A probability associated with the chisquared distribution.

Deg_freedom Required. The number of degrees of freedom.
Remarks

If argument is nonnumeric, CHISQ.INV returns the #VALUE! error value.

If probability < 0 or probability > 1, CHISQ.INV returns the #NUM! error value.

If deg_freedom is not an integer, it is truncated.

If deg_freedom < 1 or deg_freedom > 10^10, CHISQ.INV returns the #NUM! error value.
Example
Copy the example data in the following table, and paste it in cell A1 of a new Excel worksheet. For formulas to show results, select them, press F2, and then press Enter. If you need to, you can adjust the column widths to see all the data.
Formula 
Description 
Result 
=CHISQ.INV(0.93,1) 
Inverse of the lefttailed probability of the chisquared distribution for 0.93, using 1 degree of freedom. 
5.318520074 
=CHISQ.INV(0.6,2) 
Inverse of the lefttailed probability of the chisquared distribution for 0.6, using 2 degrees of freedom. 
1.832581464 