Probability Calculator

Enter the probabilities of two independent events to get every combination: both, either, exactly one, neither, and complements.

How to use the probability calculator

Enter probabilities as decimals between 0 and 1.
Results use the multiplication, addition and complement rules.

Examples

P(A) = 0.5, P(B) = 0.3

Answer: P(A∪B) = 0.65

Formulas

Binomial Probability

P (X = k) = (k n) p^{k} (1 - p)^{n - k}

Probability Rules

P (A \cup B) = P (A) + P (B) - P (A \cap B), P (A^{'}) = 1 - P (A)

Frequently asked questions