Convert Hectare (ha) to Acre (US Survey) (ac (US)) instantly.
About these units
Hectare (ha)
A hectare is equal to 10,000 m², or 0.01 km², and is the standard unit of land measurement in agriculture, forestry, and land management across most of the world. Unlike the acre, which comes from historical English land systems, the hectare is fully metric and integrates cleanly into scientific practice. Farmers use hectares to measure fields, crop yields, irrigation requirements, and livestock capacity. Foresters rely on hectares for forest inventories, timber production estimates, and biodiversity assessments. Urban planners use hectares when describing zoning, green space, and population density. The hectare is the perfect intermediate scale: large enough for meaningful land plots, and small enough to avoid unwieldy numbers when describing farms or urban districts.
Acre (US Survey) (ac (US))
The US survey acre is based on the US survey foot, making it slightly different from the international acre. With a value of 43,560 survey-square feet, it appears extensively in historical property records and federal land surveys. Because millions of acres in the United States were mapped using PLSS, the survey acre remains necessary for interpreting legal land rights, even though modern mapping often uses metric units or the international foot. This specialized acre illustrates how subtle unit differences can survive for centuries due to legal and administrative inertia.