Square Mile to Square Kilometer Converter

A square mile (mi²) is a unit of area equal to the area of a square with sides of one mile each. It equals 640 acres or approximately 2.59 square kilometers, making it suitable for measuring large geographical areas.

The square mile developed from the English mile, which was standardized in 1593. As territorial expansion and land surveying became important in English-speaking countries, particularly in North America, the square mile became a standard unit for measuring large land areas and territories.

Square miles are primarily used in the United States and United Kingdom for measuring counties, states, large properties, and geographical features. They're standard in American atlases, real estate for large properties, and government land management. Many US states report their area in square miles.

A square kilometer (km²) is a unit of area equal to the area of a square with sides of one kilometer each. It equals 1,000,000 square meters or 100 hectares, making it suitable for measuring large geographical areas.

The square kilometer emerged naturally from the metric system established during the French Revolution in 1795. As the kilometer became standardized for distance measurement, its square became the logical unit for large area measurements, particularly useful for mapping territories and countries.

Square kilometers are universally used for measuring countries, states, cities, large properties, national parks, and geographical features. They're standard in atlases, geographic surveys, urban planning, and environmental studies. Most countries report their total area in square kilometers.