Poisson Probability: λ = 4, k = 2 Events
With an average rate of 4 events per interval, the Poisson probability of exactly 2 events is approximately 14.65%.
How to use this tool
- Enter rate (λ) and events (k) in the fields above.
- Results update instantly as you type — or click Calculate.
- Read your p(x = k) and the full breakdown beneath it.
Calculate the probability of observing 2 events in a window where 4 events are expected on average, a typical call center or traffic model scenario.
Frequently asked questions
- When should I use the Poisson distribution?
- Use Poisson when counting events in a fixed interval of time or space, where events occur independently at a known average rate λ. Examples: emails per hour, accidents per week, typos per page.