Maryland property tax is based on:

Purchase price is not the basis for property tax calculation. While it may influence the assessed value when property is first purchased, taxes are based on the government's assessed value, which may differ significantly from the actual purchase price over time.

Square footage is merely one factor considered in determining assessed value. It's not the basis for taxation itself, as other factors like location, condition, and improvements also significantly impact the final assessed value.

Income approach to valuation is used primarily for commercial properties but is not the basis for property taxation in Maryland. Residential property taxes are based on assessed value, not income potential.