I would use a tool like https://www.calculator.net/rental-property-calculator.html (which is good for 99.99999% of rental calculations), but I wasn't able to easily answer questions like "what if I live in the property for the first 10 years, and then rent it out after?" "How would the cashflow look like on month 121?" "How many properties would I need to have in order to generate a yearly income needed to put a down payment on a new rental property?" I don't think I can answer the last question yet.
This is barely functional. Because this is such an unintuitive UI, I made a demo video demonstrating the scenario where the user doesn't live in the property for the first 10 years, rents it out from year 10 - year 30,and sells it at year 30. https://www.youtube.com/watch?v=zXi-gGRuj7s&feature=youtu.be
Here is the source code. https://github.com/abzgupta/doughflow.io
Looking for feedback!
[https isn't working .. the build files live in s3 and it looks like the URL doesn't support https?.. I am investigating]