There are approximately 43,560 square feet in every one acre. There are 640 acres in a square mile. Large plots of property are often measured in acres, whereas indoor measurements are commonly done in square feet.
There are 43,560 square feet in an acre. However, it's important to remember that an acre can be a variety of different shapes. It is helpful to know this conversion when one is purchasing land because while square feet are usually used in real estate, the land might have already been plotted by the Department of Land Management in acres - it's always good to double check measurements.