Rental property analysis

[Tarcizio Goncalves]

Hi everyone, 

I am curious to know how investors determine the market rents on their properties. I am using a site called rentometer and I like it. I do think that they are a little on the higher side so I wanted to know if there are other sites used by investors to determine the market rent. 

Do you just use a sites? What other strategies or tips you can give to find the market rent?

A 4-plex (strictly for investment) really caught my attention and according to rentometer, I can increase the rents by $275,  per per unit. If this is the case, My cash flow will be really nice. I just want to make sure that I know what the actual rents are before making an offer on the property. 

Thank you everyone