Binomial Distribution Calculator
Calculate exact binomial probabilities and cumulative values with an interactive PMF/CDF view for n and p.
The binomial distribution models the number of successes in a fixed number of independent Bernoulli trials. Typical examples include number of defective items in a batch or number of conversions in a campaign.
Use this calculator to evaluate exact probabilities P(X = k), ranges like P(a ≤ X ≤ b), and cumulative values P(X ≤ k).
Launch the Binomial Distribution workspace to plot the curve, inspect PDF/CDF behavior, and compute quantiles and interval probabilities.
Open Interactive Interval ProbabilityWhen should I use a binomial distribution?
Use it when each trial has two outcomes, the success probability is constant, and trials are independent.
What parameters do I need?
You need n (number of trials) and p (success probability per trial).
Can I compute cumulative probabilities?
Yes. The CDF gives cumulative probability and the interval tool gives probability over a range of k values.