Square Mile [mi²]
A square mile (mi²) is a unit of area used primarily in the United States and the UK to measure large land areas. It represents a square that is one mile long on each side.
1 square mile = 2.59 square kilometers = 640 acres.
Square miles are commonly used to describe the size of cities, counties, and large geographic regions.
Square Mile (US Survey)
The square mile (US survey) is a unit of area used in the United States for land measurement based on the US survey foot. It represents a square with sides 1 mile long, where a mile is defined using the survey foot rather than the international foot.
1 US survey mile = 5,280 US survey feet
1 square mile (US survey) ≈ 2.589998 km² (slightly different from the international square mile of 2.59 km²)
This unit is mostly used in land surveying and mapping within the US.