There are 640 acres in a square mile. This is a standard measurement that comes from the way land is divided in the United States and many other countries.
To understand this better, let’s break it down. A square mile is a unit of area that measures one mile on each side, creating a square. Since one mile is equal to 5,280 feet, a square mile is 5,280 feet by 5,280 feet, which equals 27,878,400 square feet in total.
On the other hand, an acre is defined as a unit of area that is equal to 43,560 square feet. To find out how many acres are in a square mile, you divide the total number of square feet in a square mile by the number of square feet in an acre:
27,878,400 square feet (in a square mile) ÷ 43,560 square feet (in an acre) = 640 acres.
This is why when you hear someone say there are 640 acres in a square mile, it is correct. This is a key piece of information for anyone involved in land use, real estate, or agriculture.