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 square metre?
The square metre is the SI unit of area. It is widely used in real estate, construction, interior design, and land measurement across countries that use the metric system.
Real-world uses
Square metres are the global standard for floor space in real estate listings, construction blueprints, and land surveys outside the US. Solar panel output is rated per square metre, and rental prices in most countries are quoted per m².
History
The square metre is a derived SI unit that follows naturally from the metre. It became the standard area unit as the metric system spread globally. Real estate markets worldwide adopted it as metrication displaced local units like the tsubo (Japan) and pyeong (Korea).
Common mistakes
Confusing linear metres with square metres—a room that is 3 m × 4 m is 12 m², not 7 m. Also, forgetting that when scaling dimensions by a factor, area scales by the square of that factor.
When is this conversion used?
Converting between acre and square metre 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 = 4,046.8564224 square metre
1 square metre = 1 square metre
How to convert acre to square metre
To convert acre to square metre, multiply the value by 4,046.8564224.
To convert square metre back to acre, multiply by 0.00024711.
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 square metre
| acre | square metre |
|---|---|
| 0.1 | 404.68564224 |
| 0.5 | 2,023.4282112 |
| 1 | 4,046.8564224 |
| 2 | 8,093.7128448 |
| 5 | 20,234.282112 |
| 10 | 40,468.564224 |
| 25 | 101,171.41056 |
| 50 | 202,342.82112 |
| 100 | 404,685.64224 |
| 250 | 1,011,714.1056 |
| 500 | 2,023,428.2112 |
| 1,000 | 4,046,856.4224 |
Common values
| acre | square metre | |
|---|---|---|
| A4 paper | 0.00001532 acre | 0.062 square metre |
| Parking space | 0.00308882 acre | 12.5 square metre |
| Tennis court | 0.06446238 acre | 260.87 square metre |
| Football field (soccer) | 1.76433242 acre | 7,140 square metre |
| Central Park, NYC | 842.6293508 acre | 3,410,000 square metre |