The most often used unit of measurement for land is the acre. The acre is a unit of area in the imperial and U.S. customary systems. One acre equals 4046.873sq. Meter, 43560.178 Sq. Foot. or 0.405 hectare. One mile equals 640 acres. The acre is often used in measurements for areas of land and its international symbol is ac. Acre is basically used in the United States and the United Kingdom. It is the oldest unit applied worldwide to measure vast tracts of land and has been through lots of changes all the way. The acre is a common land measurement unit used throughout the world, notably in the US, Canada, Jamaica, Spain, France, Germany, and much of South Asia, which includes Bangladesh, India, Pakistan, and Sri Lanka.