That is the exact kind of back-of-the-napkin formula I was looking for.

In the one on housing prices corrected for inflation, the red line is my approximation of an average bottom of the market.And here's a simplistic link to do a back-of-the-napkin affordability calc on a $300k home at 7% 30-yr mortgage:https://www.dollartimes.com/in...

If the sanitary conditions in your Rental Unit are such that it attracts pests of any kind, and it becomes necessary for us to undergo remediation in your Rental Unit and/or on the Premises, you will be held financially responsible for reasonable costs thereof, paid as Additional Rent.

It got me wondering if there are some good videos of people doing "back of napkin" or whiteboard math on properties. 

@Qui VanThose rules of thumb are for beginners to do a back of the napkin calculation so they don’t make a big mistake.

Of course, I'm lucky to live and be a citizen of but the pandemic has showed us how easy it is for any country to curtail individual freedoms, whatever we think about the sanitary measures taken during Covid.Then, I realized that, in normal circumstances, real estate values in developed countries like Canada should grow at the rate of inflation and that cash flows would be very meager if they weren't underpinned by the artificially low central bank manipulated interest rates.

JR I see what you mean - thank you.The thing is - Its generally very important for me to have a back-of-napkin calculation to quickly see the monthly returns or liability, you see.

I act as a GC, have a great electrician and plumber that I work with if needed (yes, they're the types of guys that write quotes on the back of a napkin, but they're licensed and do great work that always passes inspection).

@Shannon Vanderweide, considering that I just closed one where one of the bathrooms was a complete wreck, so we removed the toilet, removed the shower head, removed the shower door, put a sanitary cover thingie over the toilet waste hole, thew a bunch of boxes in there, and called it a "storage room," and considering that his was FHA which has slightly higher standards than Fannie / Freddie, I'm going to go with "No, both bathrooms do not need to be functional.

When I do my napkin math, it looks like the following:Gross rent would be 127440/yr at 90% occupancyTaxes at 10k, (from what I can tell, taxes are based on 12% cap rate)Insurance at 7k, (This is not a quote, but a guess on my part)Water 15k/yr - (I saw a 40 unit that had a 20k/yr water bill)Debt service 42k/yr for 15 yrs (me putting ~20% down borrowing ~450k)Maintenance/repairs 26k/yr (figuring by 20% of gross rent)It looks like to make decent return, I need to offer closer to 600k, or possibly a little less.