Noun

acre (plural acres)

1. (obsolete) A field.
2. A unit of surface area (symbol a. or ac.), originally as much as a yoke of oxen could plough in a day; later defined as an area 1 chain (22 yd) by 1 furlong (220 yd), or 4,840 square yards. Equivalent to about 4,046.86 square metres.
3. (in plural, informal) A large amount (of area).

   I like my new house - there’s acres of space!

Derived terms

• acre foot
• God's acre

The acre is a unit of area in a number of different systems, including the imperial and U.S. customary systems. The most commonly used acres today are the international acre and, in the United States, the survey acre. The most common use of the acre is to measure tracts of land.

One acre comprises 4,840 square yards or 43,560 square feet. While all modern variants of the acre contain 4,840 square yards, there are alternative definitions of a yard, so the exact size of an acre depends on which yard it is based on. Originally, an acre was understood as a selion of land sized at one furlong (660 ft) long and one chain (66 ft) wide; this may have also been understood as an approximation of the amount of land an ox could plough in one day. A square enclosing one acre is approximately 208 feet and 9 inches (63.6 metres) on a side. But as a unit of measure an acre has no prescribed shape; any perimeter enclosing 43,560 square feet is an acre in size.

The acre is often used to express areas of land. In the metric system, the hectare is commonly used for the same purpose. An acre is approximately 40% of a hectare.

One acre is 90.75 percent of a 100-yard (91.44-meter) long by 53.33-yard (48.77-meter) wide American football field (without the end zones). The full field, including the end zones, covers approximately 1.32 acres (0.53 ha). It is also approximately 56.68 percent of a 105-meter (344.49-foot) long by 68-meter (223.10-foot) wide Association football pitch (soccer field). It may also be remembered as 44,000 square feet, less 1%; or as the product of 66 x 660.