Acres to Square Kilometers Converter

To convert a measurement in acres to square kilometers, multiply the value by 0.004046856422. The conversion factor comes from the relationship between both units and the square meter.

For example, to convert 5 ac to square kilometers: 5 × 0.004046856422 = 0.020234282112 km².

An acre is an imperial and US customary unit of area equal to 43,560 square feet, or about 4,046.86 square meters (roughly 0.405 hectares). The acre originally meant the area a yoke of oxen could plow in a day, standardized as 1 chain by 1 furlong (66 by 660 feet). It remains the standard unit for land and farm area in the US and UK.

Common uses of acres include: Farmland and rural land size; Residential lot and property size in the US; Real estate and development parcels; Sports field and park area references.

A square kilometer is a metric unit of area equal to the area of a square one kilometer on each side, or 1,000,000 square meters. The square kilometer became the standard unit for large land areas as the metric system spread. It is used for the areas of cities, countries, lakes, and other geographic features worldwide.

Common uses of square kilometers include: Areas of cities, countries, and regions; Land, forest, and agricultural coverage; Lake and reservoir surface area; Population density (people per km²).

Here are some common values converted:

1 ac = 0.004046856422 km² 5 ac = 0.020234282112 km² 10 ac = 0.040468564224 km² 50 ac = 0.20234282112 km² 100 ac = 0.40468564224 km²