A Google Sheets™ add-on by AlmaLearning Monte Carlo Risk Simulator
Turn any Google Sheets financial model into a full risk analysis. Assign probability distributions to your inputs, mark an output cell, and run up to 100,000 Monte Carlo iterations — with tornado charts, scenario comparison, forecasting, regression, and portfolio optimization.
Monte Carlo Risk Simulator adds a Risk Simulator menu and sidebar to your spreadsheet. From there you can:
Sample from 10 probability distributions (Normal, Triangular, PERT, Lognormal, and more), with correlated inputs, seeded runs, and full statistics: percentiles, VaR, CVaR, and probability of loss.
Tornado and spider charts rank which assumptions drive your output most, plus post-simulation Spearman rank correlations.
Put best, base, and worst cases side by side with a full simulation per scenario — distributions, not just point estimates.
Create one-way and two-way data tables using true spreadsheet recalculation, rendered as charts and heat maps.
Project time series with confidence bands, and fit OLS regressions with full diagnostics — bridged directly into the simulation engine.
Run mean-variance optimization with efficient frontier charts for 5–15 assets.
Your data never leaves your browser
All computation runs locally, inside your own browser session, using scientific libraries loaded as WebAssembly. The add-on requests access only to the spreadsheet it is installed in(spreadsheets.currentonly) and permission to display its sidebar (script.container.ui). It has no server, no database, and no analytics inside the add-on — AlmaLearning never receives, stores, or transmits your spreadsheet data. See our Privacy Policy and Terms of Service.
How It Works
Assign assumptions
Select an input cell, choose a probability distribution, set its parameters. The cell turns green.
Mark a forecast
Select your model's output cell (for example, NPV) and mark it as the forecast. The cell turns blue.
Run the simulation
Choose the number of iterations and click Run. Results appear on a new sheet with a statistics table, histogram, CDF, and sensitivity charts.
Go deeper
Use the sidebar tabs for tornado analysis, scenarios, data tables, forecasting, regression, and portfolio optimization — or generate a consolidated report in one click.
Who it's for
The add-on was built for graduate finance coursework as a platform-independent alternative to Excel-only risk simulation tools. It's suited to students, instructors, analysts, and anyone who wants probabilistic analysis of a spreadsheet model. Its outputs are for educational and informational purposes and are not investment advice.
