The three numbers that matter
Cash flow is what's left each month after rent pays the mortgage and expenses. Cap rate is the property's annual net operating income (rent minus operating expenses, before the mortgage) divided by the price - a clean way to compare properties no matter how they're financed. Cash-on-cash return is your yearly cash flow divided by the actual cash you put in, so you can see how hard your money is working.
What this tool doesn't include (be honest with your numbers)
This is a first-pass screen. It doesn't include closing costs, a capital-expense reserve (roof, furnace, appliances), financing fees, or income tax. A deal that looks thin here usually gets thinner once those land, so pad your expense estimate and keep a reserve. If a property clears the bar here, it's worth a real, detailed look.
A note from an investor, not just an agent
I own rentals and have done rent-to-own and flips in the Central Alberta market, so I know the difference between a listing that looks good in photos and a deal that actually works. If you want a straight opinion on whether the numbers make sense - send it to me. I'd rather tell you to walk away from a bad deal than sell you one.