Convert Square Kilometer (km²) to Acre (ac) instantly.
About these units
Square Kilometer (km²)
A square kilometer equals one million square meters and is the standard unit for expressing large land areas, especially in geography, ecology, national planning, and environmental science. Countries, cities, national parks, forests, wetlands, and even ocean surface regions are frequently described in km². Because it provides a manageable scale for features too large for hectares or acres, it is widely used in atlases, scientific papers, and government reports. The square kilometer also plays a major role in ecology, where species ranges, habitat fragmentation, and conservation zones are measured using this unit. In geopolitics, km² help define national borders and territorial claims, making it a powerful instrument of scientific and political discourse.
Acre (ac)
An acre is a traditional Anglo-American land unit equal to 43,560 square feet, or roughly 4,047 m². It originated from medieval English farming, where an acre represented the amount of land a yoke of oxen could plow in one day—reflecting its deep agricultural roots. The acre remains widely used in the United States and the UK (in certain contexts), especially in real estate, agriculture, and land conservation. It is culturally intuitive for rural populations, where land plots have been measured in acres for centuries. The unit's longevity demonstrates how historical agricultural practices shaped modern land evaluation systems. Despite its lack of coherence with the metric system, the acre endures because of its cultural familiarity and long-standing legal integration.