Poisson Distribution CDF Calculator

For a Poisson distribution with rate parameter $\lambda >0$, the cumulative distribution function is: $$F(x;\lambda )=\sum _{i=0}^x\frac{{\lambda }^i{e}^{-\lambda }}{i!},x=0,1,2,\dots$$

* Enter a nonnegative integer $x$ and a rate $\lambda$.