Beta Distribution Calculator

The first shape parameter. In a Bayesian setting, think of α as roughly “successes + 1”; a larger α pushes the distribution toward 1.

The second shape parameter, pushing weight toward 0 (“failures + 1”). When α equals β the distribution is symmetric around 0.5.

The proportion to evaluate, between 0 and 1 — e.g. a conversion rate of 0.3. The tool reports the probability of falling below or above it.

A cumulative probability between 0 and 1; the tool returns the value x below which a share p of the distribution lies.