Potential Gross Income (PGI) is the maximum possible rent at market rent that can be expected for a given period of time at full occupancy without losses due to collections and without consideration of expenses. The period of time that income is estimated is usually a year.
For example: Rent for 2-bedroom apartments is typically $750 per month. An apartment building with 20 2-bedroom units has potential (monthly) gross income of $15,000. There is no consideration of vacancies, collection losses, or other expenses.