What is square mile?
A square mile is a unit of area in imperial and US customary systems equal to 640 acres. It is used to express the size of cities, regions, and geographic territories in the United States and United Kingdom.
Real-world uses
Square miles are used for city areas, county sizes, and population density calculations in the US and UK. Manhattan is about 23 square miles. National parks and wilderness areas are often described in square miles in American contexts.
History
The square mile became a standard geographic unit in English-speaking countries alongside the statute mile. The US Public Land Survey System, established in 1785, divided territory into 36-square-mile townships, each containing 36 one-square-mile sections.
Common mistakes
Assuming 1 square mile = 1 mile × 1 mile = 1 mi². While correct, people forget that 1 sq mi = 640 acres or about 2.59 km², leading to errors when comparing American and metric area figures.
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 square mile 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 square mile = 25,899.88110336 are
1 are = 100 square metre
How to convert square mile to are
To convert square mile to are, multiply the value by 25,899.88110336.
To convert are back to square mile, multiply by 0.00003861.
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 mile to are
| square mile | are |
|---|---|
| 0.1 | 2,589.98811034 |
| 0.5 | 12,949.94055168 |
| 1 | 25,899.88110336 |
| 2 | 51,799.76220672 |
| 5 | 129,499.4055168 |
| 10 | 258,998.8110336 |
| 25 | 647,497.027584 |
| 50 | 1,294,994.055168 |
| 100 | 2,589,988.110336 |
| 250 | 6,474,970.27584 |
| 500 | 12,949,940.55168 |
| 1,000 | 25,899,881.10336 |
Common values
| square mile | are | |
|---|---|---|
| A4 paper | 2.393833e-08 square mile | 0.00062 are |
| Parking space | 0.00000483 square mile | 0.125 are |
| Tennis court | 0.00010072 square mile | 2.6087 are |
| Football field (soccer) | 0.00275677 square mile | 71.4 are |
| Central Park, NYC | 1.31660836 square mile | 34,100 are |