Poisson Distribution Calculator
Probability of k events occurring when the average rate is λ.
Poisson(λ=4) distribution
k = 0 … 12
P(X = 3)
0.19537
P(X ≤ 3)
0.43347
P(X ≥ k)
0.7619
Mean (λ)
4
Std Dev (√λ)
2
λ is the average number of events in the interval (e.g. customers/hour, calls/day).