Here is a little calculator I built using Calculoid (https://app.calculoid.com/#/calculator/93897)
This is just a proof of concept, nothing final.
The design can be tinkered with, including the font and the color scheme.
We still need to find good default values for each field.
Average American salary = ~$50,000
Turnover rate = 20% is unrealistically low compared to the stats in this article: