How do you estimate correct rent prior to buying a rental property?

[Jack Srimani]

Hi,
I am in the process of analyzing a townhome. This is a three bedroom and one bath property. I am estimating the rent that I can have should I finalize the deal. I am using zilpy.com which states the asking price of 1200 while rentometer.com shows the 1200 price reasonalbe rent. However in the rentometer in the nearly places the rents are showing from 800 to 1000. This is confusing to me. My question is how do I accurately estimate rents for rental property for a particular area so that I am neither undercharging or overcharing. This estimation accuracy is vital for me to do my analysis of rental purchase for this property. I appreciate your help. Regards.