Rental Property Calculator vs Realtor Commission

[Pedro Miranda]

Hello everyone. I recently started using the Rental Property Calculator and immediately one question came to my mind: in the field "Rental income / Gross Monthly Income" I understand it should go the full amount the tenant will pay me each month. But what about the realtor commission? in which field should I add this info? I understand this is an important expense in a rental analisys. In a yearly bases lease, the commission can be one month of rent and this affects significantly the project income and thereafter the expected cash flow. I'm afraid this doubt can drive me to wrong investment decisions. Can anyone please help me with that question?