Convert square feet to acres
Please provide values below to convert square feet [sq ft] to acres [ac], or vice versa.
Square Foot
Definition: A square foot (symbol: sq ft or ft²) is a unit of area in the imperial and US customary systems. It is defined as the area of a square with sides of 1 foot in length.
History/origin: The square foot, like many imperial measurements, has its roots in ancient systems of measurement. The foot itself has varied throughout history, being based on the human foot in many cultures. The Romans used a foot that was approximately 11.6 modern inches. The current definition of a foot as exactly 12 inches became standardized in the UK and US in the early 19th century. The square foot naturally evolved as a unit of area measurement based on this length unit.
Current use: Square feet are commonly used in the United States, United Kingdom, Canada, and other countries that use the imperial or US customary systems for measuring building areas, real estate, and small to medium-sized spaces. Residential and commercial property sizes are typically expressed in square feet in these countries. For example, home sizes, office spaces, and retail locations are commonly advertised by their square footage. In construction and architecture, floor plans and building specifications frequently use square feet as the standard unit of area measurement.
Acre
Definition: An acre (symbol: ac) is a unit of land area measurement used in the imperial and US customary systems. One acre equals 4,840 square yards, 43,560 square feet, or approximately 4,047 square meters.
History/origin: The acre has its origins in medieval England, where it represented the amount of land that could be plowed in one day by a yoke of oxen. The term "acre" comes from the Old English word "æcer" meaning "open field." Originally, an acre was defined as the area of one chain (66 feet) by one furlong (660 feet), which equates to 43,560 square feet. This unusual number reflects its agricultural origins rather than being a simple decimal-based unit.
Current use: The acre is still widely used in the United States, United Kingdom, Canada, and many Commonwealth countries for measuring land area, especially for real estate, agriculture, and forestry. In countries that primarily use the metric system, the hectare (10,000 square meters or approximately 2.47 acres) has largely replaced the acre as the standard unit for land measurement, although the acre is sometimes still used informally.