If that number comes out lower than you expect, then you can adjust your strategy accordingly.Leverage is simply a multiplier - both on the upside and the downside.

Wouldn't it be MORE meaningful to multiply YOUR sf by market derived $ per sf?  

Part of their income is based on interest they receive on the delay between taking the money from your tenant and delivering it to your bank over 3-5 days multiplied by thousands and thousands of customers.

Multiply that times what you will be charging.

In a single family home, it's not too worrisome, but when you have a multifamily property, you're multiplying the cost by how many units you have.

I know there are light, medium, and heavy figures that you can multiply by the square footage to get a ball park number.

The Cap Rates will be different because of the price paid for the property, different rental income, different operating costs and the way each building is managed differently.The Gross Multiplier is more specific for different areas and for my analyzing the Gross Multiplier is much more important than the Cap Rate. 

You have to look at 100 deals on paper to identify 2-5 potential deals and I suggest, you make offers on all those potential deals.It's a lot of work but if you do them diligently, you will multiply your $100K initial capital 100-fold. 

My advice is to find properties that rent for x amount and multiply that number by 45 low end and 65 good to high end areas and subtract your expenses annually thus creating your offer price!

@Jaren BarnesI don’t really play in the MF sandbox but some colleagues that do are always talking about Gross Rent Multiplier.