**MonteCarlito - Monte Carlo in Excel**

MonteCarlito is a free Excel-add-in to do Monte Carlo simulations. It computes common summary stats like median and standard error, outputs them directly into Excel cells, and shows histograms.

*Properly, you'd do this in, say, Python. MonteCarlito is meant to provide a low-barrier intro to the topic for educational purposes.*

**How does it work?**

MonteCarlito is a VBA macro; just open the MonteCarlito Excel file along with your actual worksheets to use it.

**How to start a Monte Carlo sim?**

Put the number of desired Monte Carlo paths next to a cell containing a randomly fluctuating formula; select the two cells, along with some cells below; then press [Ctrl+W]. (The MonteCarlito Excel file contains a more detailed tutorial.)

**How to create histograms?**

Set the format of the cell containing the number of paths to **bold** before starting the simulation.

**How to speed it up?**

Enter a negative number of paths. This minimizes Excel during simulations, and avoids costly window refreshes.

2004+ :: GNU GPL 3.0