There are many online calculators available on websites that will allow you to see and understand potential returns from a real estate transaction. However, each calculator may use different variables in its equation, including such important items as calculations and terms of amortization, depreciation, mortgage interest paid, interest rates, property taxes, occupancy rates, analysis duration (the duration of time over which you review the data may greatly influence your results), and your tax bracket information. The more variables you try to capture, the more accurate your estimate will be regarding your potential returns.