how big is 1 acre in square feet
Acre The acre is a unit of land area used in the imperial and US customary systems. It is defined as the area of 1 chain by 1 furlong (66 by 660 feet), which is exactly equal to ​1⁄640 of a square mile, 43,560 square feet, approximately 4,047 m2, or about 40% of a hectare.
Marla (unit) The marla is a traditional unit of area that was used in India, Pakistan and Bangladesh. The marla was standardized under British rule to be equal to the square rod, or 272.25 square feet, 30.25 square yards, or 25.2929 square metres. As such, it was exactly one 160th of an acre.