Poisson Distribution Calculator
Calculate exact and cumulative Poisson probabilities using event rate λ and number of events k.
Formula:
P(X = k) = (e^-λ · λ^k) / k!
Result will appear here.
| Metric | Value |
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Privacy: calculations run locally in your browser. No inputs are stored or transmitted.
How it works
The Poisson distribution models how many events occur in a fixed interval when events happen independently at an average rate λ.
Examples
- λ = 4, k = 2 → exact probability of exactly 2 events
- P(X ≤ k) adds all exact probabilities from 0 through k
FAQ
- What does this Poisson calculator compute?
It computes exact probability P(X = k) and cumulative probability P(X ≤ k) for a Poisson distribution.
- What is lambda (λ)?
Lambda is the average rate or expected number of events in the interval.
- Can lambda be negative?
No. Lambda must be 0 or greater.
- Are calculations stored?
No. Everything runs locally in your browser.