An are is 100 square meters.
Ares to Square Kilometers Converter — a to km2
Convert Are (a) to Square Kilometer (km2) using the exact conversion factor (1 are = 0.0001 square kilometer). See the formula, worked examples, conversion table, history, and common uses.
Ares to Square Kilometers converter
Converter
Area Converter
Convert land, construction, mapping, survey, and scientific area units.
Context values
Some unit families need one extra value for a physically accurate result.
Square metric area unit.
Result = input x 100 / 1e+6.
Area uses the square meter as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Ares to Square Kilometers
Comparing Are and Square Kilometer is common in agriculture and real estate, where US land is typically measured in acres and most of the rest of the world uses hectares. Specifically: An are is 100 square meters, and square metric area unit.
Formula
square kilometers = ares × 0.0001
This factor comes from each unit's defined relationship to the category's base unit: 1 are equals 100 base units, and 1 square kilometer equals 1000000 base units, so dividing one by the other gives the direct are-to-square kilometer factor of 0.0001.
Simple example
1 a × 0.0001 = 0.0001 km2
1 are = 0.0001 square kilometers.
Real-world example
10 a × 0.0001 = 0.001 km2
10 ares = 0.001 square kilometers.
Conversion table
| Are (a) | Square Kilometer (km2) |
|---|---|
| 1 a | 0.0001 km2 |
| 5 a | 0.0005 km2 |
| 10 a | 0.001 km2 |
| 25 a | 0.0025 km2 |
| 50 a | 0.005 km2 |
| 100 a | 0.01 km2 |
Reverse conversion: Square Kilometer to Are
0.0001 km2 × 10000 = 1 a
0.0001 square kilometers = 1 are.
ares = square kilometers × 10000
For a page dedicated to this direction, see Square Kilometer to Are.
Understanding the Are (a)
An are is 100 square meters.
Understanding the Square Kilometer
Square Kilometer (km2) measures area. A square kilometer is one million square meters — the area of a 1 km × 1 km square. It is classified as a SI derived (metric prefix) unit.
Where it's used: Used worldwide for city, region, and country-scale area reporting.
Uses of the Square Kilometer today
- National and regional land-area statistics
- City and urban planning at large scale
- Geography and cartography
History of the Square Kilometer
Like other metric-prefixed area units, the square kilometer follows automatically from the kilometer once the meter was standardized in the 1790s French metric reform.
Historical origin. Square Kilometer was not the invention of a single named person; it developed through the process described above.
Square Kilometer — sources
- BIPM SI Brochure — Coherent derived units — Basis for metric-prefixed area units.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many square kilometers are in 1 are?
1 are equals 0.0001 square kilometers, using the exact defined conversion factor rather than an estimate.
How do I convert are to square kilometer?
Multiply the are value by 0.0001. The converter above does this instantly to whatever precision you set.
How do I convert square kilometer back to are?
Use the reverse factor: 1 square kilometer equals 10,000 ares. You can also use the swap control in the converter above to flip the direction instantly.
What is a are?
Are (a) is a unit of area.
What is a square kilometer?
Square Kilometer (km2) measures area. A square kilometer is one million square meters — the area of a 1 km × 1 km square. It is classified as a SI derived (metric prefix) unit.
Is the are to square kilometer conversion exact?
Yes. Both are and square kilometer are defined by fixed standards rather than physical artifacts, so the factor of 0.0001 used above is exact to as many digits as you choose to display.