What does acre mean?
An acre is a traditional unit of land area, equal to 4,840 square yards or approximately 4,047 square metres — roughly the size of an American football field without its end zones. It remains the standard measure for describing land in the United States, the United Kingdom, and other countries that use customary units, appearing constantly in real estate listings, farm reports, and planning documents. The word also carries a looser figurative sense, describing any broad stretch of open ground, as in 'acres of parking lot'. Historically, an acre represented the amount of land a team of oxen could plough in one day, which explains its irregular dimensions: one furlong long by one chain wide. Although most of the world has adopted the metric hectare, the acre endures because of its deep roots in agriculture, law, and everyday descriptions of property, making it essential vocabulary for anyone discussing land, farming, or real estate in English-speaking countries.
A unit of land area equal to 4,840 square yards (approximately 4,047 square metres).
"The estate covers three hundred acres."
Typically appears in plural or with fractions; the singular usually follows a numeral.
A plot or expanse of land, especially arable or pastoral land, considered informally rather than as a precise measurement.
"Acres of open moorland stretched to the horizon."
Standard plural; used for any quantity greater than one. The phrase 'half an acre' uses the singular form after a fraction.
"The vineyard occupies fifteen acres of south-facing slope."
An acre was originally the amount of land a yoke of oxen could plough in a single day — which is why it's an oddly specific 4,840 square yards.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of acre
The word 'acre' comes from Old English 'æcer', meaning an open field or cultivated land, which derives from Proto-Germanic '*akraz' and ultimately from the Proto-Indo-European root '*h₂eǵros-', meaning field or pasture. This same root gave Latin 'ager' (field), from which English derives 'agriculture' and 'agrarian'. Cognates appear across Germanic languages, such as German 'Acker' (field). Originally denoting unclosed land generally, the word narrowed over the Middle Ages to mean a specific measured quantity of arable ground.
Related word forms
How acre is actually used
Always used with plural or fractional forms in real estate and agricultural contexts; singular 'acre' typically appears after a number ('three acres', 'half an acre'). In British usage, acres coexist with hectares in official contexts but remain common in everyday speech and property listings.
Easily confused with acre
An acre is about 4,047 square metres, whereas a hectare is a metric unit of exactly 10,000 square metres, so one hectare equals roughly 2.47 acres.