Statistical Library

Triangular Distribution in Google Sheets

Minimum, most likely, maximum — the analyst's fast estimate.

Interactive Sandbox

10,000 simulations running live in your browser.

Base Value 100
7085100115130
P10 Worst Case 83.3
P50 Median 100.2
P90 Best Case 116.4

When to use it

The Triangular distribution is the fastest way to encode expert opinion into a model. Ask a subject-matter expert for three numbers — their pessimistic floor, their most-likely estimate, and their optimistic ceiling — and you're done. It's not as rigorous as PERT but it's fast, transparent, and easy to explain to stakeholders who don't want to hear about shape parameters.

  • Quick project timeline estimates from expert interviews
  • Sales pipeline range modeling with discrete scenarios
  • Budget line-item uncertainty when limited historical data exists
  • Scenario analysis in three-point estimating (PMI method)

How to build it

Native Sheets Formula

=IF(RAND()<(c-a)/((b-a)*(c-a)),a+SQRT(RAND()*(b-a)*(c-a)),c-SQRT((1-RAND())*(c-a)*(c-b)))

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.