Critical Value Calculators

Critical values play a central role in hypothesis testing. They define the boundary between the rejection region and the acceptance region of a probability distribution. If your test statistic falls beyond the critical value, you reject the null hypothesis. Otherwise, you fail to reject it.

Different statistical tests use different probability distributions. That means the critical value you need depends on:

• The type of test you’re performing

• The significance level (α)

• The degrees of freedom (if required)

Below you’ll find all our critical value calculators for the major distributions used in hypothesis testing, including Z, t, F, chi-square, and correlation (r) critical values.