used by people in more than 220 countries!

Below you will find descriptions and links to 4 free statistics calculators for computing values associated with event occurrence.

If you like, you may also use the search page to help you find what you need.

This calculator will compute the probability that event A will not occur (i.e., the complementary probability of A), given the probability of event A occurring.

This calculator will compute the probability of event A occurring, given that event B has occurred (i.e., the conditional probability of A), given the joint probability of events A and B, and the probability of event B.

This calculator will compute the probability of two events A and B occurring together (i.e., the joint probability of A and B), given the conditional probability of event A, and the probability of event B.

This calculator will compute the probability of event A or event B occurring (i.e., the union probability for A and B), given the probability of event A, the probability of event B, and the joint probability of events A and B.