Offer your thoughts or opinion on the input financial query or topic using your financial background.

What is the fastest way to retire, using passive income on real estate 
You can't calculate how many houses it will take. To do so you would have to know how much you can charge in rent compared to how much is costs to run that particular location. If the desirability of that location changes, so does the ability to rent the place, and so does the amount you can charge. It is possible to create a business in real estate that would allow you to generate retirement income. But you would be focusing all your income in your retirement years on one segment of the entire investment universe. The diversification would have to come from spreading the money through different types of real estate: condo, apartments, houses, commercial, warehouse, light industrial. You would even have to decide whether you want them all in one micro-market, or spread throughout a larger market, or an even wider area diversification.  As your empire grew and you approached retirement age you would have to decide if you wanted to liquidate your investments to minimize risk. The long leases that provides stability of income would make it hard to sell quickly if the market in one area started to weaken.