# Critical Value Calculator

Calculates the **critical value** for the following distributions:**t critical value calculator, z critical value calculator, f critical value calculator, chi square critical value calculator.**

### What is the critical value?

The critical value the boundary between the accepted region (green) and the rejected region (red). Under the assumption that the H_{0} is correct, the probability to get the critical value or more extreme value (red) is the significance level (α).

What is more extreme?

Two-tailed: smaller than the small value or larger than the large value.

Left-tailed: smaller than the small value.

Right-tailed: larger than the large value.

### Z critical value calculator

To calculate the critical value for the z statistic, choose the normal distribution and enter the mean and standard deviation.

For a standard normal distribution enter μ = 0 and &sigma = 1.

### T critical value calculator

To calculate the critical value for the t statistic, choose the T distribution and enter the degrees of freedom (n - 1).

### F critical value calculator

To calculate the critical value for the F statistic, choose the F distribution and enter the degrees of freedom (n - 1).

### Chi square critical value calculator

To calculate the critical value for the Chi-square statistic, choose the Chi-square distribution and enter and enter the degrees of freedom.

### Standard deviation

The statistic's standard deviation. For example, for the average test, you should enter σ/√n.