Mathlean · Online math workspace
Poisson distribution calculator
Calculate Poisson count probabilities for a specified rate.
How to use this calculator
Edit PDF(PoissonDistribution(rate),count), or use CDF for cumulative probability.
Tap the math below to edit it and see the result. Once a result is ready, press Tab on a hardware keyboard to accept it. Outside a matrix, Return completes the line; the phone math keyboard has the same Return action.
Try it here
Interactive tools require JavaScript. You can read the guide and example without it.
What to know
The rate must be nonnegative and the count an integer. The model's equal mean/variance assumption may not fit real data.
Mathlean combines visual mathematical input with computation and canvas tools. Results depend on the expression and available engine support; check important answers independently.