# Inverse Chi-squared distribution

This tool calculates the Inverse of Chi-squared Cumulative Distribution Function.

## Inverse Chi-squared Distribution formulas

X is a random variable following a exponential distribution of parameter `k > 0` (degrees of freedom).

The inverse of the cumulative distribution function F(x) is also called the 'quantile function', denoted Q(x). We have,

`F(x) = (gamma(k/2,x/2))/(Gamma(k/2))`

where `Gamma(x)` is the gamma function,

and `gamma(x)` is the incomplete gammma function,

`Q(x) = F^(-1)(x)`

## See also

Chi-squared distribution Probabilities

Chi-squared distribution Chart

Statistics Calculators