Often, growth means that operating cost also grow, e.g., due to higher infrastructure cost, more worker salaries, expansion into more economic markets with more/new regulations to tackle, ....

That could be at some fixed percentage in a simple model, and is a quite relevant factor which this tool completely misses.

So go for that spreadsheet, it can start really simple, with minimal parameters like this has - but being able to adapt and expand it over time as ones business growths and changes allows for much better and more efficient planning.

Startup Growth Calculator - https://news.ycombinator.com/item?id=8040448 - July 2014 (30 comments)

and a bit more:

Startup Growth Calculator - https://news.ycombinator.com/item?id=16802351 - April 2018 (1 comment)

Startup Growth Calculator – if nothing changes, are you alive or dead? - https://news.ycombinator.com/item?id=10766922 - Dec 2015 (1 comment)

After dragging any of the sliders for a bit, the console reports:

``` SecurityError: Attempt to use history.replaceState() more than 100 times per 30 seconds ```

and it freezes.

Goes well with the kind of slide that says:

"If 100M people give us ten dollars, we have a billion"