Wauvel

Excel like a finance pro.

← The library

Statistical function

BETA.DIST

Returns the beta distribution, often used to model proportions between 0 and 1.

Rarely usedDifficulty 1550 · AdvancedUsage rank #418 of 520
Practice · 2 questions →

When to use it

The beta distribution on 0 to 1, shaped by alpha and beta. It models proportions, completion percentages, and Bayesian estimates of a rate.

The shape of it

Syntax
=BETA.DIST(x, alpha, beta, cumulative, [A], [B])

Worked examples

  • Symmetric case

    =BETA.DIST(0.5,2,2,TRUE) 0.5

    Symmetric when alpha equals beta.

  • Density

    =BETA.DIST(0.5,2,2,FALSE) 1.5

    The density peaks at 0.5.

  • Bayesian rate

    =BETA.DIST(0.25,2,3,TRUE) 0.26171875

    Probability the rate is at most 25% after 1 success and 2 failures with a uniform prior.

Worth knowing

  • After s successes and f failures with a flat prior, the rate follows Beta(s+1, f+1).
  • Optional A and B rescale the range from 0-1 to A-B, useful for PERT task durations.
  • BETA.INV gives percentiles.

Where it goes wrong

  • #NUM! when alpha or beta is not positive or x is outside A to B.
  • The cumulative flag is required.

Related

Learn the moves here — or let Wauvel run them on your numbers.

Meet your AI CFO →

One CFO-grade Excel tip a week

A short, practical email for finance operators — functions, shortcuts, and the moves that save an afternoon. Free, unsubscribe anytime.