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Convert square feet to acres

Please provide values below to convert square foot [ft^2] to acre [ac], or vice versa.


Square foot

Definition: A square foot (symbol: sq ft) is a unit of area used in the imperial and US customary systems (UCS). It is defined as the area of a square with one-foot sides. One square foot equals 144 square inches.

History/origin: The origin of the square foot can be seen in the term itself. It is a measurement derived from the area of a square with a side length measured in feet.

Current use: The square foot is mainly used in the United States but is also used to some extent in countries such as the United Kingdom, Canada, Malaysia, Singapore, Pakistan, Bangladesh, India, and Hong Kong. In these countries, area in real estate, architecture, and of interior spaces is often specified in terms of square footage.


Definition: An acre (symbol: ac) is a unit of land area used in the imperial and US customary systems. It is defined as the area of 1 chain (66 feet) by 1 furlong (660 feet), which is exactly equal to 1/640 of a square mile, 43,560 square feet, or exactly 4046.8564224 square meters.

History/origin: In the Middle Ages, the acre was defined as the area that a yoke (pair) of oxen could typically plow within one day, using a wooden plow. Before the metric system was adopted, many countries used their own versions of the acre. The most commonly used acre today, the international acre, is based on the international yard, which was defined in 1959.

Current use: Acres are used in countries including the United States, the UK, Ghana, India, Canada, and others. The United States (US) uses both international as well as US survey acres (~4047 square meters), which vary based on which type of yard is used in the measurement. However, area measurements are typically not accurate enough for the difference between the two acre measurements to be detectable.

Square Foot to Acre Conversion Table

Square Foot [ft^2]Acre [ac]
0.01 ft^22.2956841138659E-7 ac
0.1 ft^22.2956841138659E-6 ac
1 ft^22.29568E-5 ac
2 ft^24.59137E-5 ac
3 ft^26.88705E-5 ac
5 ft^20.0001147842 ac
10 ft^20.0002295684 ac
20 ft^20.0004591368 ac
50 ft^20.0011478421 ac
100 ft^20.0022956841 ac
1000 ft^20.0229568411 ac

How to Convert Square Foot to Acre

1 ft^2 = 2.29568E-5 ac
1 ac = 43560 ft^2

Example: convert 15 ft^2 to ac:
15 ft^2 = 15 × 2.29568E-5 ac = 0.0003443526 ac

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