An acre is a unit of area commonly used in the United States and other countries to measure large plots of land. To be precise, one acre is defined as 43,560 square feet.
This measurement comes from the historical land practices where an acre was originally defined as the amount of land that could be plowed by a team of oxen in one day. Over time, as the need for standardization arose, the acre was standardized to its current measurement in square feet.
To visualize it, an acre can be thought of as a rectangle that measures 208.71 feet by 208.71 feet, or alternatively, it can be described as being roughly equivalent to about 90% of a football field (not including the end zones). Understanding this conversion can be very useful, especially for real estate transactions, land development projects, and agricultural planning.