Acre [ac] to Square Kilometer [km2] Converter

Definition: An acre (ac) is a unit of area used in the imperial and US customary systems. It is equal to 43,560 square feet, or approximately 4,047 square meters.

History/origin: The acre has ancient origins, dating back to medieval England. It was originally defined as the area of land that a yoke of oxen could plow in a day.

Current use: Acres are commonly used in agriculture, land management, and real estate to measure larger areas of land. It's a prevalent unit in the United States and some other countries.

Definition: A square kilometer (km²) is a unit of area equal to a square that is 1 kilometer on each side. It is a multiple of the square meter, the SI unit of area.

History/origin: The square kilometer is derived from the kilometer, which is part of the metric system established in France in the late 18th century. The metric system was designed to be a standardized and coherent system of measurement based on decimal multiples.

Current use: Square kilometers are used to measure large areas, such as the size of cities, countries, lakes, and other geographical features. It's a common unit in geography, cartography, and environmental studies.