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Binomial Distribution Calculator

A free online tool for calculating probabilities of events following binomial distribution.
Binomial distribution of probability describes likelihoods of all possible outcomes of n successive trials where in each trial there is the same probability p of "success" (i.e. of a defined result like e.g. a head when tossing a coin). The probability P of seeing exactly x successes in n successive trials is given by the formula:
P(X=x) =
x!(n - x)!

n>0, 0≤x≤n, 0≤p≤1



Number of trials:n =

Probability of success in one trial:p =

Calculate the probability of x successes in n trials:
x =
Calculate the total probability of numbers of successes from the interval x1 - x2:
x1 = x2 =

P(X = x):

P(X ≤ x):

P(X ≥ x):