Poisson Distribution Calculator

P(X = x):
P(X < x):
P(X ≤ x):
P(X > x):
P(X ≥ x):

Understanding Poisson Distribution

The Poisson distribution models the probability of a specific number of events occurring in a fixed interval of time or space, assuming these events occur independently at a constant average rate.

Formula

P(X = k) = (λᵏ × e⁻λ) / k!

where:

λ (lambda) = average rate of success

k = number of successes

e = Euler's number (≈ 2.71828)

Common Applications

  • Customer arrivals per hour
  • Network traffic analysis
  • Quality control in manufacturing
  • Natural phenomena occurrence rates