An acre is a unit area that is use to measure the size of a plot of land. An acre has 4,840 square yards or 43,560 square feet. An acre is only about 40% of a hectare. An acre is the area of chain by one furlong (66 feet x 660 feet).
An acre is about 90% of an American football field. An American football field is about 1.32 acre or 44,000 square feet which is 440 more feet than an acre.