Binomial Probability Calculator

Calculate exact and cumulative probabilities for binomial distributions

Number of Trials (n):

Number of Successes (k):

Probability of Success (p) - between 0 and 1:

About Binomial Probability

The binomial probability formula calculates the probability of getting exactly k successes in n independent trials, where each trial has probability p of success.

Formula: P(X = k) = C(n,k) × p^k × (1-p)^(n-k)

Example: What is the probability of getting exactly 3 heads in 10 coin flips?