Beta Distribution in Google Sheets
Model probabilities, percentages, and win rates.
Interactive Sandbox
10,000 simulations running live in your browser.
When to use it
The Beta distribution lives on [0, 1] by design, making it perfect for modeling quantities that are themselves probabilities or proportions: conversion rates, project completion percentages, market share, and win/loss rates. Its two shape parameters (α, β) let you encode a wide range of beliefs — from flat uncertainty to skewed expert opinions. It's also the Bayesian conjugate prior for Bernoulli trials, making it native to A/B test analysis.
- Conversion rate uncertainty in marketing and growth models
- Project completion percentage distribution in EVM
- Win rate estimation for sales pipeline forecasting
- A/B test posterior belief updating
How to build it
Native Sheets Formula
=BETA.INV(RAND(), alpha, beta) Using native RAND() requires you to copy this formula 10,000 times manually, which severely lags the browser.
The MonteSheet Way
MonteSheet uses a local browser engine to run 100,000 iterations in 4 seconds without writing a single formula.
Explore more distributions
The bell curve that powers every financial forecast.
For anything that can't go below zero — prices, durations, deal sizes.
Minimum, most likely, maximum — the analyst's fast estimate.
The project manager's secret weapon.
Every outcome equally likely — maximum uncertainty.
Count how many times something rare will happen.
Binary outcomes: win or lose, ship or slip, pass or fail.
Equal odds across a fixed set of whole-number outcomes.