.:@ The rent is $ 2,600 per monthWhich means, you must be entering a different figure for your (other than P&I) expenses to arrive at a monthly cash flow of $582.42 (instead of the "50% rule" which does arrive at $502.72).All that likely means is that breaking the expenses down as accurately as you can, for this property, you're calculating it to be approximately 47% expenses, which you've itemized.Not that much difference really. ie. "50%" is still a good rough napkin-estimate, right?

With AirBnb especially, getting public opinion on the side of the hotels in the name of "sanitary regulation" and "the public good" was child's play for the lobbyist veterans of the hospitality industry.

But it makes for easy math when doing back of the napkin analysis on properties.

.$2100 for PITI, $300 for PM, $150 for vacancy, $300 for cap ex and maintenance (some would recommend 10% each for Cap Ex and Maintenance) You'd actually be cash flowing about $50-$150/month (back of the napkin math). 

Heck, we lost all of our cool decorative napkin holders!

She then went on to explain what systems need to have a value assigned to them: -HVAC systems ( motors, compressors, boilers, furnace, chillers, pipes, ducts, radiators) -Plumbing systems (including pipes, drains, valves, sinks, bathtubs, toilets, water and sanitary sewer collection equipment, and site utility equipment used to distribute water and waste to and from the property line and between buildings and other permanent structures)-Electrical systems (including wiring, outlets, junction boxes, lighting fixtures and associated connectors, and site utility equipment used to distribute electricity from the property line to and between buildings and other permanent structures)-Gas distribution systems (including associated pipes and equipment used to distribute gas to and from the property line and between buildings or permanent structures)...

I looked down in the tank and a feminine napkin looked like a pontoon boat floating around .

Any quick dirty way to find property numbers good bad without fancy spreadsheets or apps or calculators just to put on napkin and boom you see great potential especially when you are on field.

For a quick back of the napkin financials, the main things to consider are your acquisition cost, hard costs - material and labor, soft costs - design and permit fees etc, and commissions, holding costs, and financing.hard costs can be hard to estimate and varies widely across the nation.

Yeah if I'm trying to do a quick back-of-the-napkin running the numbers.