Probability of At Least One

Calculate P(at least one success) in n trials.

Probability of At Least One Event

Fill in the fields below to calculate

Probability per Trial (p)

Probability of success on each trial

Number of Trials (n):

Enter your values above to see the result.

Your Results

P(At Least One Success)

P(None)

Expected Successes

Formula

At Least One:

P = 1 - (1 - p)^n

Probability of None:

P(none) = (1 - p)^n

Expected Successes:

E = n × p

where p = probability per trial, n = number of trials

Pro Tips

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