Best tools for rental valuation?

[Nathan Guyette]

I know Zillow and other websites have tools to give you valuations on properties, but what other tools are there? 

[Seth Nadreau]

Either hire an experienced and competent realtor to perform a CMA or BPO for you or hire an appraiser. Period.

Even Zillow encourages you to consult an appraiser. Zestimates use macro-market data that seldom understands the market. There are many factors that someone who works in the market daily will understand that a computer program simply won't. AVMs have gotten better... but they still are not reliable and most have standard deviations (remember high school statistics?) of at least 20% and confidence scores under 70. Too risky to trust your money to any automated system.

The sales comparable approach to value will dominate regardless of cash flow if it's a single family home or 1-4 units and is being financed. 

Other approaches (Cap Rates, GRMS, etc.) are not nearly as reliable when talking about residential properties... and if anyone mentions $/square foot... kick them.