I am always skeptical of the accuracy of any website/app that spits outs a fair market rent based on just a few parameters. I've always found it best to review Craigslist/Zillow/HotPad for comparable rentals in the area. This allows me to take the condition/finish and specific location (i.e. corner lot, on thoroughfare etc.) into consideration as well as what is included in rent (ex. water, gas, and/or electric).
I agree with @Josiah Kay . Go to a website like Realtor.com or Zillow, use the map functions to zoom in the area around your property, see what the rents are and fine toon base on specifics, such as size, finishes, specific locations, utilities, etc.
OMG, I can’t believe if spelled ‘tune’ as ‘toon’. Damn spell check!