# CHIINV

Formulas / CHIINV
Return the appropriate x value based on the accuracy of CHIDIST.
`CHIINV(probability,deg_freedom)`
• probability - required, a probability associated with the chi-squared distribution
• deg_freedom - required, the number of degrees of freedom

## Examples

• `=CHIINV(A2,A3) = 18.306973`

because that is the one-tailed probability of the chi-squared distribution.

• `=CHIINV(A2,A3`

)The example returns #NUM! because a nonnumeric argument causes CHIINV to return the #VALUE! error.

• `=CHIINV(A2,A3)`

This example returns 1 because probability is required to be a number.

## Summary

The CHIINV function is used to calculate the inverse of the CHIDIST function, which calculates the probability that a Chi-Square distributed random variable with df degrees of freedom is greater than or equal to x. CHIINV uses a search process to find the right value of x.

• The CHIINV function is used to find the correct value of x by evaluating the CHIDIST function.
• It is the inverse of the CHIDIST function and returns the corresponding probability of a given value.