An acre is a land area of 43,560 square feet.
The acre is a statute measure in the United States, in the United Kingdom and in almost all countries of the former British Empire: in most it is lawful to “use for trade” if given as supplementary information and is not used for land registration.
In the United States both the international acre and the US survey acre are in use, but they differ by only two parts per million, see below. The most common use of the acre is to measure tracts of land.
