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.

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 square metre to are is useful in the area domain when comparing values across different measurement standards or applying formulas that require a specific unit.

Worked examples

1 square metre = 0.01 are

1 are = 100 square metre

How to convert square metre to are

To convert square metre to are, multiply the value by 0.01.

To convert are back to square metre, multiply by 100.

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: square metre to are

square metreare
0.10.001
0.50.005
10.01
20.02
50.05
100.1
250.25
500.5
1001
2502.5
5005
1,00010

Common values

square metreare
A4 paper0.062 square metre0.00062 are
Parking space12.5 square metre0.125 are
Tennis court260.87 square metre2.6087 are
Football field (soccer)7,140 square metre71.4 are
Central Park, NYC3,410,000 square metre34,100 are