This Poisson distribution calculator finds the probability of a specific number of events occurring within a fixed interval of time or space, based on a known average rate. Just enter the average rate (λ) and the number of events you’re interested in (x). For example, the Poisson distribution calculator can tell you the probability of receiving 3 emails in an hour if you typically receive 5 emails per hour.
The calculator displays several probabilities related to the number of events you enter. It also shows a Poisson distribution graph with probabilities for all possible event counts, highlighting your selected value in red. This graph helps you see how your chosen number of events (x) fits within the range of likely outcomes based on the average rate (λ). Below the Poisson distribution calculator, you’ll find additional information and examples for using it. See all my Statistical Calculators!