What is acre?
An acre is a unit of area in imperial and US customary systems equal to 43,560 square feet. It is the standard unit for measuring agricultural land, property lots, and parks in the United States and United Kingdom.
Real-world uses
Acres are used for land parcels, farm sizes, and real estate in the US, UK, and some Commonwealth countries. Zoning laws often specify minimum lot sizes in acres. An American football field (including end zones) is about 1.32 acres.
History
The acre originated in medieval England as the amount of land a yoke of oxen could plough in one day. The word comes from Old English "æcer." It was standardized as a strip 1 furlong (660 ft) by 1 chain (66 ft), yielding 43,560 square feet.
Common mistakes
Assuming an acre is a square measure with specific dimensions—it is 43,560 sq ft but can be any shape. Also, confusing acres with hectares: 1 acre ≈ 0.405 hectares, so roughly 2.5 acres make one hectare.
What is are?
An are is a metric unit of area equal to 100 square metres. While largely replaced by the hectare for most practical uses, it is still referenced in some European countries for measuring agricultural plots.
Real-world uses
The are (100 m²) is used in some European countries for small land parcels and garden plots. In France, small agricultural plots and building lots may be listed in ares. It is most commonly encountered as the basis for the hectare (100 ares).
History
The are was defined in 1795 during the creation of the metric system in France as 100 square metres. Though the hectare eclipsed it in common usage, the are remains a legally recognized metric unit in several European countries.
Common mistakes
Confusing the are (a unit of area equal to 100 m²) with the word "are" (verb). Also, many people are unfamiliar with this unit and do not realize that 1 hectare = 100 ares.
When is this conversion used?
Converting between acre and are is common when working across metric and imperial systems, such as international trade, travel between countries with different measurement standards, or following instructions from a different region.
Worked examples
1 acre = 40.46856422 are
1 are = 100 square metre
How to convert acre to are
To convert acre to are, multiply the value by 40.46856422.
To convert are back to acre, multiply by 0.02471054.
Measurement standards
The square metre is the SI derived unit of area. The hectare (10,000 m²) is accepted for use with the SI by the BIPM, particularly for land measurement, though it is not an SI unit itself.
Did you know?
Vatican City, the world's smallest independent state, covers just 0.44 km² (about 109 acres) — smaller than many golf courses. By contrast, Russia spans over 17.1 million km², nearly 39 million times larger.
Quick reference: acre to are
| acre | are |
|---|---|
| 0.1 | 4.04685642 |
| 0.5 | 20.23428211 |
| 1 | 40.46856422 |
| 2 | 80.93712845 |
| 5 | 202.34282112 |
| 10 | 404.68564224 |
| 25 | 1,011.7141056 |
| 50 | 2,023.4282112 |
| 100 | 4,046.8564224 |
| 250 | 10,117.141056 |
| 500 | 20,234.282112 |
| 1,000 | 40,468.564224 |
Common values
| acre | are | |
|---|---|---|
| A4 paper | 0.00001532 acre | 0.00062 are |
| Parking space | 0.00308882 acre | 0.125 are |
| Tennis court | 0.06446238 acre | 2.6087 are |
| Football field (soccer) | 1.76433242 acre | 71.4 are |
| Central Park, NYC | 842.6293508 acre | 34,100 are |