The Poisson distribution is one of the most commonly used distributions in statistics.

This calculator finds Poisson probabilities associated with a provided Poisson mean and a value for a random variable.

λ (average rate of success)

x (random variable)

P(X = 3): 0.14037

P(X ≤ 3): 0.26503

P(X > 3): 0.73497

P(X ≥ 3): 0.87535