Acre (ac)
The acre is 43,560 square feet, approximately 4,047 square meters, or about 0.4047 hectares. It is the unit that Americans, Britons, and many others around the world use when buying, selling, and describing land. A suburban residential lot might be a quarter to half an acre, a small farm 10 to 50 acres, and a large ranch thousands of acres. The acre's size is awkward to visualize precisely, but a useful approximation is about 75 percent of a football field or roughly the area of 16 tennis courts. Despite having no clean relationship to any modern unit, the acre persists because it is deeply woven into property law, land registries, and the everyday language of real estate in English-speaking countries.
Definition
One acre is exactly 43,560 square feet, 4,840 square yards, or 1/640 of a square mile. It equals exactly 4,046.8564224 square meters or approximately 0.40469 hectares. An acre is roughly the area of a rectangle 66 feet wide and 660 feet long, though it can be any shape. There are exactly 640 acres in one square mile.
History
The acre is one of the oldest English units still in daily use. Its name comes from the Old English æcer, meaning open field. In medieval England the acre was defined as the amount of land a yoke of oxen could plow in one day, though the precise area varied by region. Eventually it was standardized as a strip of land one chain wide and one furlong long, which is 66 feet by 660 feet, giving exactly 43,560 square feet. The chain and furlong themselves derive from agricultural practice: a furlong, meaning furrow long, was the length of a plowed furrow, and a chain was the length of the surveyor's chain used by Edmund Gunter in 1620. The US Public Land Survey System divided the American West into sections of 640 acres, each being one square mile. The international yard and pound agreement of 1959 fixed the acre at exactly 4,046.8564224 square meters. Despite metrication in the UK and elsewhere, the acre remains in common use for land measurement in the United States, the United Kingdom, Ireland, Canada, Australia, and India.
Common Uses
Land sales and real estate dominate the acre's usage. Residential lots in the United States are typically quoted in fractions of an acre. Farmland prices are stated per acre. Timber sales specify acreage. National parks, wildlife refuges, and conservation areas report their size in acres in the US and often in the UK. Zoning codes specify minimum lot sizes in acres. Water rights in the western United States use the acre-foot, the volume of water that would cover one acre to a depth of one foot, as a fundamental unit of water allocation.
Did You Know? Facts About Acre
- An American football field, including both end zones, is about 1.32 acres. Without the end zones, it is about 1.1 acres.
- The original Disneyland in Anaheim, California, sits on about 85 acres, while Walt Disney World in Florida covers roughly 25,000 acres, about the size of San Francisco.
- Central Park in New York City covers about 843 acres, which is roughly 3.4 square kilometers or about 6 percent of Manhattan's total area.
- The acre-foot, a unit of water volume used in the western United States, is the amount of water needed to cover one acre to a depth of one foot. One acre-foot is about 326,000 US gallons.
- The word acreage entered English to mean any large tract of land, even when the area has not been measured in acres. People speak of acreage in metric countries too.