Free @RISK Alternative: Monte Carlo Analysis in the Browser

@RISK by Lumivero is excellent software with a price to match, and plenty of people need only a slice of what it does. This page is the honest comparison: what the free tools on this site cover, and where the commercial package still earns its keep.

What the free tools cover

• Probabilistic STOIIP for reserves ranges.
• Construction cost risk with contingency computed from the distribution.
• Slope stability with probability of failure.
• Geothermal power ranges from the volumetric method.
• Each runs 10,000 seeded simulations with triangular inputs, P90 P50 P10, a histogram, and a tornado chart.

Everything runs in the browser with nothing installed and nothing uploaded: your data stays on your machine, results print to PDF, and every tool carries a Project bar that remembers your inputs and can assemble a report.

Where @RISK still wins

@RISK simulates any spreadsheet model with dozens of distribution types, correlations, and optimization. General purpose risk modeling on your own formulas remains its home ground.

The verdict

For the standard engineering cases these four tools cover, the free versions give the same statistical story with zero setup: open the page and the simulation has already run. Start with the links above; if you outgrow them, you will know exactly what to buy and why.

Related Calculators and Reference

• Construction Cost Risk Calculator, for the construction cost version of the same simulation.
• Geothermal Risk Calculator, when the uncertain quantity is geothermal output rather than money.
• Slope Stability Risk Calculator, for slope stability expressed as a probability rather than one factor of safety.
• NIST e-Handbook of Statistical Methods, the reference treatment of the statistics a Monte Carlo run rests on.